feat(maestro): add SpawnSheet bottom sheet composable (#269)

Preset chip row, searchable project list, debounced directory
autocomplete, and a branch/worktree picker matching the web spawn
modal, wired to SpawnViewModel and a self-contained snackbar for
submit errors.

android/app/build.gradle.kts

@@ -71,6 +71,9 @@ dependencies {
     implementation(libs.kotlinx.coroutines.android)
 
     testImplementation(libs.junit)
+    testImplementation(libs.kotlinx.coroutines.test)
+    testImplementation(libs.okhttp.mockwebserver)
+    testImplementation(libs.turbine)
 
     androidTestImplementation(libs.androidx.test.ext.junit)
     androidTestImplementation(libs.androidx.espresso.core)

android/app/src/main/java/pt/naps/maestro/MainActivity.kt

@@ -8,25 +8,37 @@ import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.material3.DrawerValue
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalDrawerSheet
+import androidx.compose.material3.ModalNavigationDrawer
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.launch
 import pt.naps.maestro.connection.DaemonLink
 import pt.naps.maestro.connection.DaemonPrefs
 import pt.naps.maestro.connection.LinkState
+import pt.naps.maestro.ui.sidebar.SidebarContent
 import pt.naps.maestro.ui.theme.MaestroTheme
 
 class MainActivity : ComponentActivity() {
     private lateinit var daemonLink: DaemonLink
 
+    @OptIn(ExperimentalMaterial3Api::class)
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
@@ -38,8 +50,35 @@ class MainActivity : ComponentActivity() {
         setContent {
             MaestroTheme {
                 val linkState by daemonLink.state.collectAsState()
-                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->
-                    PlaceholderScreen(modifier = Modifier.padding(innerPadding), linkState = linkState)
+                val drawerState = rememberDrawerState(DrawerValue.Closed)
+                val scope = rememberCoroutineScope()
+
+                ModalNavigationDrawer(
+                    drawerState = drawerState,
+                    drawerContent = {
+                        ModalDrawerSheet(modifier = Modifier.width(320.dp)) {
+                            SidebarContent(
+                                catalogStore = daemonLink.catalog,
+                                onOpenSession = { scope.launch { drawerState.close() } },
+                            )
+                        }
+                    },
+                ) {
+                    Scaffold(
+                        modifier = Modifier.fillMaxSize(),
+                        topBar = {
+                            TopAppBar(
+                                title = { Text("Maestro") },
+                                navigationIcon = {
+                                    IconButton(onClick = { scope.launch { drawerState.open() } }) {
+                                        Text("☰")
+                                    }
+                                },
+                            )
+                        },
+                    ) { innerPadding ->
+                        PlaceholderScreen(modifier = Modifier.padding(innerPadding), linkState = linkState)
+                    }
                 }
             }
         }

android/app/src/main/java/pt/naps/maestro/ui/sidebar/ActivityRail.kt

@@ -0,0 +1,91 @@
+package pt.naps.maestro.ui.sidebar
+
+import androidx.compose.animation.animateColorAsState
+import androidx.compose.animation.core.InfiniteTransition
+import androidx.compose.animation.core.LinearEasing
+import androidx.compose.animation.core.RepeatMode
+import androidx.compose.animation.core.animateFloat
+import androidx.compose.animation.core.infiniteRepeatable
+import androidx.compose.animation.core.rememberInfiniteTransition
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.width
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.unit.dp
+import pt.naps.maestro.data.ActivityState
+
+/** docs/SIDEBAR.md: the rail's width in the web client. Android mirrors it in
+ * density-independent pixels rather than raw pixels. */
+val ACTIVITY_RAIL_WIDTH = 7.dp
+
+private val RAIL_ACTIVE = Color(0xFF3DDC84)
+private val RAIL_IDLE = Color(0xFF9AA0A6)
+private val RAIL_AWAITING = Color(0xFFF5A623)
+private val RAIL_ERROR = Color(0xFFE5484D)
+
+/** Colour per activity state (docs/SIDEBAR.md's colour table): `Starting`
+ * shares `Idle`'s colour, and an unrecognised state degrades to `Idle` so
+ * rendering never fails (Precedence). */
+fun activityColor(activity: ActivityState): Color =
+    when (activity) {
+        ActivityState.Active -> RAIL_ACTIVE
+        ActivityState.AwaitingInput -> RAIL_AWAITING
+        ActivityState.Error -> RAIL_ERROR
+        ActivityState.Idle, ActivityState.Starting -> RAIL_IDLE
+    }
+
+/** The accessible name the rail carries, since colour is never the only
+ * signal (docs/SIDEBAR.md). */
+fun activityStateWord(activity: ActivityState): String =
+    when (activity) {
+        ActivityState.Active -> "Active"
+        ActivityState.Idle -> "Idle"
+        ActivityState.Starting -> "Starting"
+        ActivityState.AwaitingInput -> "Awaiting input"
+        ActivityState.Error -> "Error"
+    }
+
+/** A held bar that pulses its alpha between 1 and [minAlpha] every
+ * [periodMs] — the blink/flash motion `AwaitingInput`/`Error` earn. */
+@Composable
+private fun InfiniteTransition.pulsingAlpha(minAlpha: Float, periodMs: Int): Float {
+    val alpha by animateFloat(
+        initialValue = 1f,
+        targetValue = minAlpha,
+        animationSpec = infiniteRepeatable(
+            animation = tween(durationMillis = periodMs, easing = LinearEasing),
+            repeatMode = RepeatMode.Reverse,
+        ),
+        label = "activity-rail-alpha",
+    )
+    return alpha
+}
+
+/** The card's rail: a coloured bar in the gutter, full card height. It paints
+ * for every card, `Idle` included, and carries motion only for states that
+ * need attention — a hard blink for `AwaitingInput`, a fast flash for
+ * `Error`. `Active` and `Idle` stay solid; colour alone is their signal. */
+@Composable
+fun ActivityRail(activity: ActivityState, modifier: Modifier = Modifier) {
+    val color by animateColorAsState(targetValue = activityColor(activity), label = "activity-rail-color")
+    val infinite = rememberInfiniteTransition(label = "activity-rail-motion")
+    val alpha = when (activity) {
+        ActivityState.AwaitingInput -> infinite.pulsingAlpha(minAlpha = 0.35f, periodMs = 600)
+        ActivityState.Error -> infinite.pulsingAlpha(minAlpha = 0.25f, periodMs = 220)
+        else -> 1f
+    }
+    Box(
+        modifier = modifier
+            .fillMaxHeight()
+            .width(ACTIVITY_RAIL_WIDTH)
+            .semantics { contentDescription = activityStateWord(activity) }
+            .background(color.copy(alpha = alpha)),
+    )
+}

android/app/src/main/java/pt/naps/maestro/ui/sidebar/FolderNode.kt

@@ -0,0 +1,58 @@
+package pt.naps.maestro.ui.sidebar
+
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+
+/** docs/SIDEBAR.md: a collapsible directory in the sidebar tree. An expanded
+ * folder's cards are one row away, so it carries no highlight of its own —
+ * only a collapsed header is ever a keyboard-walk stop, but that distinction
+ * belongs to the caller driving the walk, not this composable. */
+@Composable
+fun FolderNode(
+    label: String,
+    collapsed: Boolean,
+    onToggle: () -> Unit,
+    modifier: Modifier = Modifier,
+    depthPadding: Int = 0,
+    content: @Composable () -> Unit,
+) {
+    Column(modifier = modifier) {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .clickable(onClick = onToggle)
+                .padding(start = depthPadding.dp, top = 6.dp, bottom = 6.dp, end = 8.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Text(
+                text = if (collapsed) "▸" else "▾",
+                style = MaterialTheme.typography.labelMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            Spacer(Modifier.width(6.dp))
+            Text(
+                text = label,
+                style = MaterialTheme.typography.labelMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+            )
+        }
+        AnimatedVisibility(visible = !collapsed) {
+            Column { content() }
+        }
+    }
+}

android/app/src/main/java/pt/naps/maestro/ui/sidebar/SessionCard.kt

@@ -0,0 +1,242 @@
+package pt.naps.maestro.ui.sidebar
+
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.combinedClickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.DropdownMenu
+import androidx.compose.material3.DropdownMenuItem
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import pt.naps.maestro.data.InTheWay
+import pt.naps.maestro.data.Session
+import pt.naps.maestro.data.SessionStatus
+
+/** docs/SIDEBAR.md: a card is always two lines behind an activity rail —
+ * line 1 the name, line 2 the adaptive meta line. Long-press opens a context
+ * menu (Rename / Kill / Spawn similar); the daemon confirms rename and kill
+ * only through the callbacks the caller supplies. */
+@OptIn(ExperimentalFoundationApi::class)
+@Composable
+fun SessionCard(
+    session: Session,
+    nowMs: Long,
+    modifier: Modifier = Modifier,
+    depthPadding: Int = 0,
+    onOpen: (Session) -> Unit = {},
+    onRename: (Session, String) -> Unit = { _, _ -> },
+    onKill: (Session) -> Unit = {},
+    onSpawnSimilar: (Session) -> Unit = {},
+) {
+    var menuExpanded by remember { mutableStateOf(false) }
+    var renaming by remember { mutableStateOf(false) }
+    var confirmingKill by remember { mutableStateOf(false) }
+
+    val running = session.status == SessionStatus.Running
+    val name = sessionName(session)
+    val muted = isProvisionalName(session)
+
+    Row(
+        modifier = modifier
+            .fillMaxWidth()
+            .combinedClickable(
+                onClick = { onOpen(session) },
+                onLongClick = { menuExpanded = true },
+            )
+            .padding(start = (8 + depthPadding).dp, end = 8.dp, top = 6.dp, bottom = 6.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        ActivityRail(activity = session.activity, modifier = Modifier.height(36.dp))
+        Spacer(Modifier.width(8.dp))
+        Column(modifier = Modifier.fillMaxWidth()) {
+            Text(
+                text = name,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+                color = when {
+                    !running -> MaterialTheme.colorScheme.onSurfaceVariant
+                    muted -> MaterialTheme.colorScheme.onSurfaceVariant
+                    else -> MaterialTheme.colorScheme.onSurface
+                },
+                style = MaterialTheme.typography.bodyMedium,
+            )
+            MetaLine(session = session, nowMs = nowMs)
+        }
+    }
+
+    DropdownMenu(expanded = menuExpanded, onDismissRequest = { menuExpanded = false }) {
+        DropdownMenuItem(
+            text = { Text("Rename") },
+            onClick = {
+                menuExpanded = false
+                renaming = true
+            },
+        )
+        DropdownMenuItem(
+            text = { Text("Spawn similar") },
+            onClick = {
+                menuExpanded = false
+                onSpawnSimilar(session)
+            },
+        )
+        DropdownMenuItem(
+            text = { Text("Kill") },
+            onClick = {
+                menuExpanded = false
+                confirmingKill = true
+            },
+        )
+    }
+
+    if (renaming) {
+        RenameDialog(
+            initial = customSessionName(session) ?: "",
+            onCommit = {
+                renaming = false
+                onRename(session, it)
+            },
+            onCancel = { renaming = false },
+        )
+    }
+
+    if (confirmingKill) {
+        KillConfirmDialog(
+            session = session,
+            onConfirm = {
+                confirmingKill = false
+                onKill(session)
+            },
+            onCancel = { confirmingKill = false },
+        )
+    }
+}
+
+/** Line 2, left to right: `[duration] [detail] command [diff stat | exited]`
+ * — the line itself is unconditional, only its fragments are adaptive. */
+@Composable
+fun MetaLine(session: Session, nowMs: Long, modifier: Modifier = Modifier) {
+    val heldMs = activityHeldMs(session.activity_since, nowMs)
+    val duration = if (heldMs != null && heldMs >= META_LINE_MIN_HOLD_MS) {
+        activityDurationLabel(heldMs)
+    } else {
+        null
+    }
+    val blockers = sessionBlockers(session)
+
+    Row(modifier = modifier.fillMaxWidth(), verticalAlignment = Alignment.CenterVertically) {
+        if (duration != null) {
+            Text(
+                text = duration,
+                color = activityColor(session.activity),
+                style = MaterialTheme.typography.labelSmall,
+            )
+            Spacer(Modifier.width(6.dp))
+        }
+        if (session.activity_detail != null) {
+            Text(
+                text = session.activity_detail,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+                style = MaterialTheme.typography.labelSmall,
+                modifier = Modifier.weight(1f, fill = false),
+            )
+            Spacer(Modifier.width(6.dp))
+        }
+        Text(
+            text = programName(session.command),
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+            style = MaterialTheme.typography.labelSmall,
+        )
+        if (blockers != null) {
+            Spacer(Modifier.width(6.dp))
+            BlockedFragment(blockers)
+        }
+        if (session.status == SessionStatus.Dead) {
+            Spacer(Modifier.width(6.dp))
+            Text(
+                text = "exited",
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                style = MaterialTheme.typography.labelSmall,
+            )
+        }
+    }
+}
+
+@Composable
+private fun BlockedFragment(blockers: InTheWay) {
+    Row(verticalAlignment = Alignment.CenterVertically) {
+        blockerStats(blockers).forEachIndexed { index, stat ->
+            if (index > 0) Spacer(Modifier.width(4.dp))
+            Text(
+                text = stat.text,
+                style = MaterialTheme.typography.labelSmall,
+                color = when (stat.kind) {
+                    "add" -> MaterialTheme.colorScheme.primary
+                    "del" -> MaterialTheme.colorScheme.error
+                    else -> MaterialTheme.colorScheme.onSurfaceVariant
+                },
+            )
+        }
+    }
+}
+
+@Composable
+private fun RenameDialog(initial: String, onCommit: (String) -> Unit, onCancel: () -> Unit) {
+    var text by remember { mutableStateOf(initial) }
+    AlertDialog(
+        onDismissRequest = onCancel,
+        title = { Text("Rename session") },
+        text = {
+            OutlinedTextField(
+                value = text,
+                onValueChange = { text = it },
+                singleLine = true,
+                keyboardOptions = KeyboardOptions(imeAction = ImeAction.Done),
+            )
+        },
+        confirmButton = { TextButton(onClick = { onCommit(text.trim()) }) { Text("Rename") } },
+        dismissButton = { TextButton(onClick = onCancel) { Text("Cancel") } },
+    )
+}
+
+@Composable
+private fun KillConfirmDialog(session: Session, onConfirm: () -> Unit, onCancel: () -> Unit) {
+    val blockers = sessionBlockers(session)
+    AlertDialog(
+        onDismissRequest = onCancel,
+        title = { Text("Kill “${sessionName(session)}”?") },
+        text = {
+            Text(
+                if (blockers != null) {
+                    "This worktree has unsaved work: ${formatInTheWay(blockers)}. Killing may be refused unless forced."
+                } else {
+                    "This ends the session's process. This can't be undone."
+                },
+            )
+        },
+        confirmButton = { TextButton(onClick = onConfirm) { Text("Kill") } },
+        dismissButton = { TextButton(onClick = onCancel) { Text("Cancel") } },
+    )
+}

android/app/src/main/java/pt/naps/maestro/ui/sidebar/SessionFormatting.kt

@@ -0,0 +1,161 @@
+package pt.naps.maestro.ui.sidebar
+
+import java.time.Instant
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.jsonPrimitive
+import pt.naps.maestro.data.InTheWay
+import pt.naps.maestro.data.NameSource
+import pt.naps.maestro.data.Session
+
+/** docs/SIDEBAR.md: a state held shorter than this has no duration fragment. */
+const val META_LINE_MIN_HOLD_MS: Long = 30_000L
+
+/** Payloads predating #102 default `activity_since` to the Unix epoch;
+ * anything implausibly old is "never observed" rather than a huge duration. */
+private val PLAUSIBLE_EPOCH_MS = Instant.parse("2010-01-01T00:00:00Z").toEpochMilli()
+
+/** Milliseconds held in the current activity state, or `null` when `since` is
+ * missing/unparsable/implausible. Mirrors the web's `activityHeldMs`. */
+fun activityHeldMs(since: String?, nowMs: Long): Long? {
+    if (since.isNullOrEmpty()) return null
+    val t = runCatching { Instant.parse(since).toEpochMilli() }.getOrNull() ?: return null
+    if (t < PLAUSIBLE_EPOCH_MS) return null
+    return (nowMs - t).coerceAtLeast(0L)
+}
+
+/** `<60s` whole seconds, `<60m` whole minutes, else whole hours — floored
+ * everywhere so the counter never shows a duration the state hasn't reached. */
+fun activityDurationLabel(heldMs: Long): String {
+    val seconds = heldMs / 1000
+    if (seconds < 60) return "${seconds}s"
+    val minutes = seconds / 60
+    if (minutes < 60) return "${minutes}m"
+    return "${minutes / 60}h"
+}
+
+/** The session's own name (#125), without the command fallback: `null` for a
+ * session that was never given one. */
+fun customSessionName(session: Session): String? {
+    val element = session.metadata["name"] ?: return null
+    val primitive = element as? JsonPrimitive ?: return null
+    if (!primitive.isString) return null
+    return primitive.content.takeIf { it.isNotEmpty() }
+}
+
+/** Line 1's name: `metadata.name` if present, else the command line. */
+fun sessionName(session: Session): String = customSessionName(session) ?: session.command
+
+/** Where the session's name came from (#131), read leniently: anything
+ * unrecognised — including a session named before the field existed — reads
+ * as [NameSource.User], so an existing name is never dimmed or overwritten. */
+fun sessionNameSource(session: Session): NameSource {
+    val element = session.metadata["name_source"] as? JsonPrimitive ?: return NameSource.User
+    return when (element.jsonPrimitive.content) {
+        "Generated" -> NameSource.Generated
+        "Haiku" -> NameSource.Haiku
+        else -> NameSource.User
+    }
+}
+
+/** Whether line 1 renders the name muted (#131): a handle the daemon
+ * generated at spawn and may still replace with one derived from the first
+ * prompt. */
+fun isProvisionalName(session: Session): Boolean =
+    customSessionName(session) != null && sessionNameSource(session) == NameSource.Generated
+
+/** One fragment of the compact blocked-work stat (docs/SIDEBAR.md). `kind`
+ * picks the colour; `text` is what the card prints. */
+data class BlockerStat(val kind: String, val text: String)
+
+/** #83: this session's blocked-work breakdown when something actually blocks
+ * an unforced kill; `null` while clear or not yet probed. */
+fun sessionBlockers(session: Session): InTheWay? {
+    val w = session.blocked_work ?: return null
+    val blocked = w.uncommitted_files > 0 || w.untracked_files > 0 || w.unpushed_commits > 0
+    return if (blocked) w else null
+}
+
+/** The blocked-work breakdown as diff notation: `+124 -18 ?3 ↑2`. A tree whose
+ * only tracked change carries no line delta falls back to the file count
+ * (`~2`) rather than claiming `+0 -0`. */
+fun blockerStats(w: InTheWay): List<BlockerStat> {
+    val stats = mutableListOf<BlockerStat>()
+    if (w.insertions > 0 || w.deletions > 0) {
+        if (w.insertions > 0) stats += BlockerStat("add", "+${w.insertions}")
+        if (w.deletions > 0) stats += BlockerStat("del", "-${w.deletions}")
+    } else if (w.uncommitted_files > 0) {
+        stats += BlockerStat("files", "~${w.uncommitted_files}")
+    }
+    if (w.untracked_files > 0) stats += BlockerStat("untracked", "?${w.untracked_files}")
+    if (w.unpushed_commits > 0) stats += BlockerStat("unpushed", "↑${w.unpushed_commits}")
+    return stats
+}
+
+/** The spelled-out phrasing shared by the kill refusal and every client's
+ * tooltip, so no two describe the same tree differently. */
+fun formatInTheWay(w: InTheWay): String {
+    val parts = mutableListOf<String>()
+    fun push(n: Int, unit: String) {
+        if (n <= 0) return
+        parts += if (n == 1) "1 $unit" else "$n ${unit}s"
+    }
+    push(w.uncommitted_files, "uncommitted file")
+    push(w.untracked_files, "untracked file")
+    push(w.unpushed_commits, "unpushed commit")
+    return if (parts.isNotEmpty()) parts.joinToString(", ") else "no unsaved work"
+}
+
+private val ENV_ASSIGNMENT = Regex("^[A-Za-z_][A-Za-z0-9_]*=.*$")
+private val PLAIN_WRAPPERS = setOf("sudo", "env")
+private val DLX_CAPABLE = setOf("pnpm", "yarn")
+
+/** The program a command line runs — never its arguments (docs/SIDEBAR.md).
+ * Looks through leading `FOO=bar` assignments, `sudo`/`env` wrappers (and
+ * their own flags), and JS-toolchain launchers (`npx`, `bunx`, `pnpm`/`yarn
+ * dlx`), then basenames what is left. A command that is nothing but wrappers
+ * is returned as written rather than as an empty string. */
+fun programName(command: String): String {
+    val trimmed = command.trim()
+    val words = trimmed.split(Regex("\\s+")).filter { it.isNotEmpty() }
+    if (words.isEmpty()) return trimmed
+
+    var i = 0
+    while (i < words.size && ENV_ASSIGNMENT.matches(words[i])) i++
+    while (i < words.size && words[i] in PLAIN_WRAPPERS) {
+        i++
+        while (i < words.size && (ENV_ASSIGNMENT.matches(words[i]) || words[i].startsWith("-"))) i++
+    }
+    if (i >= words.size) return basename(words.last())
+
+    when {
+        words[i] in DLX_CAPABLE && words.getOrNull(i + 1) == "dlx" -> i += 2
+        words[i] == "npx" || words[i] == "bunx" -> i += 1
+        words[i] == "bun" && words.getOrNull(i + 1) == "x" -> i += 2
+    }
+    val program = words.getOrNull(i) ?: return basename(words.last())
+    return basename(program)
+}
+
+private fun basename(path: String): String = path.substringAfterLast('/')
+
+/** Sessions are grouped by the repository they belong to (#265): a
+ * worktree's `base_repo`, or the session's own `cwd` when it owns none. */
+fun sessionGroupKey(session: Session): String = session.worktree?.base_repo ?: session.cwd
+
+/** One folder in the sidebar tree: a repo/cwd group and the sessions in it,
+ * sorted by name. */
+data class SessionGroup(val key: String, val label: String, val sessions: List<Session>)
+
+/** Group sessions by [sessionGroupKey], each group sorted by name and the
+ * groups themselves sorted by label. */
+fun groupSessions(sessions: Collection<Session>): List<SessionGroup> =
+    sessions
+        .groupBy(::sessionGroupKey)
+        .map { (key, members) ->
+            SessionGroup(
+                key = key,
+                label = key.trimEnd('/').substringAfterLast('/').ifEmpty { key },
+                sessions = members.sortedBy { sessionName(it).lowercase() },
+            )
+        }
+        .sortedBy { it.label.lowercase() }

android/app/src/main/java/pt/naps/maestro/ui/sidebar/SidebarContent.kt

@@ -0,0 +1,123 @@
+package pt.naps.maestro.ui.sidebar
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateMapOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.delay
+import pt.naps.maestro.connection.CatalogStore
+import pt.naps.maestro.data.Session
+import pt.naps.maestro.data.Uuid
+
+/** A clock that advances at least once every 30s (docs/SIDEBAR.md), ticked
+ * faster than that so a duration's cutover lands within one visible frame. */
+@Composable
+fun rememberTickingNowMs(periodMs: Long = 5_000L): Long {
+    var now by remember { mutableStateOf(System.currentTimeMillis()) }
+    LaunchedEffect(periodMs) {
+        while (true) {
+            delay(periodMs)
+            now = System.currentTimeMillis()
+        }
+    }
+    return now
+}
+
+/** Assembles the full sidebar from the [CatalogStore] built in #264: sessions
+ * grouped into collapsible folders by repository, each rendered as a
+ * two-line [SessionCard] behind its [ActivityRail]. */
+@Composable
+fun SidebarContent(
+    catalogStore: CatalogStore,
+    onOpenSession: (Session) -> Unit,
+    modifier: Modifier = Modifier,
+    onRenameSession: (Uuid, String) -> Unit = { _, _ -> },
+    onKillSession: (Uuid) -> Unit = {},
+    onSpawnSimilar: (Session) -> Unit = {},
+) {
+    val sessions by catalogStore.sessions.collectAsState()
+    SidebarContent(
+        sessions = sessions.values.toList(),
+        onOpenSession = onOpenSession,
+        modifier = modifier,
+        onRenameSession = onRenameSession,
+        onKillSession = onKillSession,
+        onSpawnSimilar = onSpawnSimilar,
+    )
+}
+
+/** Same as the [CatalogStore]-driven overload, but takes the session list
+ * directly — the shape used by tests and previews. */
+@Composable
+fun SidebarContent(
+    sessions: List<Session>,
+    onOpenSession: (Session) -> Unit,
+    modifier: Modifier = Modifier,
+    onRenameSession: (Uuid, String) -> Unit = { _, _ -> },
+    onKillSession: (Uuid) -> Unit = {},
+    onSpawnSimilar: (Session) -> Unit = {},
+) {
+    val nowMs = rememberTickingNowMs()
+    val groups = remember(sessions) { groupSessions(sessions) }
+    val collapsed = remember { mutableStateMapOf<String, Boolean>() }
+
+    Column(modifier = modifier.fillMaxSize()) {
+        Text(
+            text = "Sessions",
+            style = MaterialTheme.typography.titleMedium,
+            modifier = Modifier.padding(16.dp),
+        )
+        if (groups.isEmpty()) {
+            Box(modifier = Modifier.fillMaxSize().padding(16.dp)) {
+                Text(
+                    text = "No sessions",
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+            return
+        }
+        LazyColumn(modifier = Modifier.fillMaxSize()) {
+            for (group in groups) {
+                val isCollapsed = collapsed[group.key] == true
+                item(key = "folder:${group.key}") {
+                    FolderNode(
+                        label = group.label,
+                        collapsed = isCollapsed,
+                        onToggle = { collapsed[group.key] = !isCollapsed },
+                        depthPadding = 8,
+                    ) {
+                        Column {
+                            for (session in group.sessions) {
+                                SessionCard(
+                                    session = session,
+                                    nowMs = nowMs,
+                                    depthPadding = 16,
+                                    onOpen = onOpenSession,
+                                    onRename = { s, name -> onRenameSession(s.id, name) },
+                                    onKill = { s -> onKillSession(s.id) },
+                                    onSpawnSimilar = onSpawnSimilar,
+                                )
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

android/app/src/main/java/pt/naps/maestro/ui/spawn/SpawnModel.kt

@@ -0,0 +1,117 @@
+package pt.naps.maestro.ui.spawn
+
+import kotlinx.serialization.json.JsonPrimitive
+import pt.naps.maestro.data.CreateSessionRequest
+import pt.naps.maestro.data.SessionView
+import pt.naps.maestro.data.SpawnPreset
+import pt.naps.maestro.data.WorktreeSpec
+
+/** Tools whose sessions can render as a structured (ACP) transcript instead
+ * of a raw terminal. Mirrors `STRUCTURED_VIEW_TOOLS` in
+ * `web/src/components/spawn/model.ts`. */
+private val STRUCTURED_VIEW_TOOLS = setOf("claude", "codex")
+
+/** Commands that just launch another program, looked through to find the
+ * real one: `env -i codex` and `sudo codex` both resolve to `codex`. */
+private val WRAPPER_PROGRAMS = setOf("env", "sudo", "nohup", "command")
+
+private val ENV_ASSIGNMENT = Regex("[A-Za-z_][A-Za-z0-9_]*=.*")
+
+/** Program a command line would run, stripped of leading `FOO=bar`
+ * assignments, known wrappers, its own arguments, and any path prefix. A
+ * simplified stand-in for the shell-grammar-aware `splitCommand` the web
+ * client uses — good enough for the preset commands and the common
+ * `env FOO=1 claude` shapes the spawn form actually produces. */
+internal fun resolveProgram(command: String): String {
+    val words = command.trim().split(Regex("\\s+")).filter { it.isNotEmpty() }
+    var i = 0
+    while (i < words.size) {
+        while (i < words.size && words[i].matches(ENV_ASSIGNMENT)) i++
+        if (i >= words.size) return ""
+        val word = words[i].substringAfterLast('/').lowercase()
+        if (word !in WRAPPER_PROGRAMS) return word
+        i++
+        while (i < words.size && words[i].startsWith("-")) i++
+    }
+    return ""
+}
+
+fun supportsStructuredView(command: String): Boolean = resolveProgram(command) in STRUCTURED_VIEW_TOOLS
+
+/** Where a worktree's branch comes from: freshly created (default) or picked
+ * from the repository's existing branches. Mirrors `WorktreeBranchMode` in
+ * `web/src/components/spawn/model.ts`. */
+enum class WorktreeBranchMode { New, Existing }
+
+/** The spawn form's current values, gathered at submit time. Mirrors
+ * `SpawnFormValues` in `web/src/components/spawn/model.ts`. */
+data class SpawnFormValues(
+    val command: String,
+    val cwd: String,
+    val name: String,
+    val structuredView: Boolean,
+    val autoApprove: Boolean,
+    val worktreeEnabled: Boolean,
+    val worktreeBranch: String,
+    val worktreeBranchMode: WorktreeBranchMode,
+)
+
+sealed interface SpawnBuildResult {
+    data class Ok(val request: CreateSessionRequest) : SpawnBuildResult
+    data class Error(val message: String) : SpawnBuildResult
+}
+
+/** Turns validated form values into a `POST /api/sessions` body, or an error
+ * message when something required is missing. Mirrors `buildSpawnRequest` in
+ * `web/src/components/spawn/model.ts`. */
+fun buildSpawnRequest(values: SpawnFormValues, baseRepo: String?): SpawnBuildResult {
+    if (values.cwd.isBlank()) return SpawnBuildResult.Error("Pick a working directory.")
+    if (values.command.isBlank()) return SpawnBuildResult.Error("Pick a command (or fill the custom command).")
+
+    val name = values.name.trim()
+    val metadata = if (name.isNotEmpty()) mapOf("name" to JsonPrimitive(name)) else emptyMap()
+
+    var worktree: WorktreeSpec? = null
+    if (values.worktreeEnabled) {
+        val branch = values.worktreeBranch.trim()
+        if (baseRepo.isNullOrBlank()) {
+            return SpawnBuildResult.Error("Worktree needs a directory inside a git repository.")
+        }
+        if (branch.isEmpty()) {
+            return SpawnBuildResult.Error(
+                if (values.worktreeBranchMode == WorktreeBranchMode.Existing) "Pick an existing branch."
+                else "Worktree requires a branch name.",
+            )
+        }
+        worktree = WorktreeSpec(
+            base_repo = baseRepo,
+            branch = branch,
+            create_branch = values.worktreeBranchMode != WorktreeBranchMode.Existing,
+        )
+    }
+
+    return SpawnBuildResult.Ok(
+        CreateSessionRequest(
+            cwd = values.cwd,
+            command = values.command,
+            metadata = metadata,
+            worktree = worktree,
+            view = if (values.structuredView && supportsStructuredView(values.command)) {
+                SessionView.Structured
+            } else {
+                SessionView.Terminal
+            },
+            auto_approve = values.autoApprove,
+        ),
+    )
+}
+
+/** Built-ins shown when the daemon's `/api/info` presets haven't loaded yet
+ * (or can't be fetched). Mirrors `FALLBACK_PRESETS` in
+ * `web/src/components/spawn/model.ts`, reordered per #269's chip row. */
+val FALLBACK_PRESETS: List<SpawnPreset> = listOf(
+    SpawnPreset(id = "claude", label = "Claude", command = "claude"),
+    SpawnPreset(id = "codex", label = "Codex", command = "codex"),
+    SpawnPreset(id = "zsh", label = "Zsh", command = "zsh"),
+    SpawnPreset(id = "custom", label = "Custom…", command = ""),
+)

android/app/src/main/java/pt/naps/maestro/ui/spawn/SpawnSheet.kt

@@ -0,0 +1,432 @@
+package pt.naps.maestro.ui.spawn
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.Button
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.RadioButton
+import androidx.compose.material3.SheetState
+import androidx.compose.material3.Snackbar
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import pt.naps.maestro.data.BranchInfo
+import pt.naps.maestro.data.Project
+import pt.naps.maestro.data.Session
+import pt.naps.maestro.data.SpawnPreset
+
+/** Bottom sheet spawn form (#269), matching the web spawn modal's flow:
+ * a preset chip row, a searchable project list, a raw-path autocomplete
+ * fallback, a branch/worktree picker, a session name, and the
+ * structured-view toggle. [SpawnSheet] wires this to a live [SpawnViewModel];
+ * [SpawnSheetContent] is the pure, state-driven body used by previews and
+ * tests. */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun SpawnSheet(
+    viewModel: SpawnViewModel,
+    onDismiss: () -> Unit,
+    onSpawned: (Session) -> Unit,
+    modifier: Modifier = Modifier,
+    sheetState: SheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true),
+) {
+    val state by viewModel.state.collectAsState()
+
+    ModalBottomSheet(onDismissRequest = onDismiss, sheetState = sheetState, modifier = modifier) {
+        SpawnSheetContent(
+            state = state,
+            onSelectPreset = viewModel::selectPreset,
+            onCustomCommandChange = viewModel::setCustomCommand,
+            onStructuredViewChange = viewModel::setStructuredView,
+            onProjectQueryChange = viewModel::setProjectQuery,
+            onSelectProject = viewModel::selectProject,
+            onCwdChange = viewModel::setCwd,
+            onPickDirSuggestion = viewModel::pickDirSuggestion,
+            onWorktreeEnabledChange = viewModel::setWorktreeEnabled,
+            onBranchModeChange = viewModel::setBranchMode,
+            onNewBranchChange = viewModel::setNewBranch,
+            onExistingBranchChange = viewModel::setExistingBranch,
+            onNameChange = viewModel::setName,
+            onReroll = viewModel::rerollName,
+            onDismissError = viewModel::dismissError,
+            onSubmit = { viewModel.submit(onSpawned) },
+        )
+    }
+}
+
+@Composable
+fun SpawnSheetContent(
+    state: SpawnUiState,
+    onSelectPreset: (String) -> Unit,
+    onCustomCommandChange: (String) -> Unit,
+    onStructuredViewChange: (Boolean) -> Unit,
+    onProjectQueryChange: (String) -> Unit,
+    onSelectProject: (Project) -> Unit,
+    onCwdChange: (String) -> Unit,
+    onPickDirSuggestion: (String) -> Unit,
+    onWorktreeEnabledChange: (Boolean) -> Unit,
+    onBranchModeChange: (WorktreeBranchMode) -> Unit,
+    onNewBranchChange: (String) -> Unit,
+    onExistingBranchChange: (String) -> Unit,
+    onNameChange: (String) -> Unit,
+    onReroll: () -> Unit,
+    onDismissError: () -> Unit,
+    onSubmit: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val snackbarHostState = remember { SnackbarHostState() }
+    LaunchedEffect(state.error) {
+        val message = state.error ?: return@LaunchedEffect
+        snackbarHostState.showSnackbar(message)
+        onDismissError()
+    }
+
+    Box(modifier = modifier.fillMaxWidth()) {
+        Column(
+            modifier = Modifier
+                .fillMaxWidth()
+                .verticalScroll(rememberScrollState())
+                .padding(horizontal = 16.dp)
+                .padding(bottom = 16.dp),
+            verticalArrangement = Arrangement.spacedBy(16.dp),
+        ) {
+            Text("Spawn session", style = MaterialTheme.typography.titleMedium)
+
+            PresetRow(
+                presets = state.presets,
+                selectedPresetId = state.selectedPresetId,
+                onSelectPreset = onSelectPreset,
+            )
+            if (state.isCustomSelected) {
+                OutlinedTextField(
+                    value = state.customCommand,
+                    onValueChange = onCustomCommandChange,
+                    label = { Text("Command") },
+                    placeholder = { Text("bash -l") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth(),
+                )
+            }
+
+            ProjectPicker(
+                query = state.projectQuery,
+                onQueryChange = onProjectQueryChange,
+                projects = state.visibleProjects,
+                loading = state.projectsLoading,
+                selectedPath = state.selectedProjectPath,
+                homeDir = state.homeDir,
+                onSelectProject = onSelectProject,
+            )
+
+            DirAutocompleteField(
+                cwd = state.cwd,
+                suggestions = state.dirSuggestions,
+                onCwdChange = onCwdChange,
+                onPickSuggestion = onPickDirSuggestion,
+            )
+
+            BranchSection(
+                enabled = state.worktreeEnabled,
+                onEnabledChange = onWorktreeEnabledChange,
+                baseRepo = state.baseRepo,
+                mode = state.branchMode,
+                onModeChange = onBranchModeChange,
+                newBranch = state.newBranch,
+                onNewBranchChange = onNewBranchChange,
+                branches = state.branches,
+                branchesLoading = state.branchesLoading,
+                existingBranch = state.effectiveExistingBranch,
+                onExistingBranchChange = onExistingBranchChange,
+            )
+
+            Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth()) {
+                OutlinedTextField(
+                    value = state.name,
+                    onValueChange = onNameChange,
+                    label = { Text("Session name") },
+                    placeholder = { Text("named after your first prompt") },
+                    singleLine = true,
+                    modifier = Modifier.weight(1f),
+                )
+                Spacer(Modifier.width(8.dp))
+                TextButton(onClick = onReroll) { Text("Reroll") }
+            }
+
+            if (supportsStructuredView(state.command)) {
+                Row(verticalAlignment = Alignment.CenterVertically) {
+                    Checkbox(checked = state.structuredView, onCheckedChange = onStructuredViewChange)
+                    Text("Structured view")
+                }
+            }
+
+            Button(
+                onClick = onSubmit,
+                enabled = !state.submitting,
+                modifier = Modifier.fillMaxWidth(),
+            ) {
+                if (state.submitting) {
+                    CircularProgressIndicator(modifier = Modifier.height(18.dp), strokeWidth = 2.dp)
+                } else {
+                    Text("Spawn")
+                }
+            }
+        }
+
+        SnackbarHost(hostState = snackbarHostState, modifier = Modifier.align(Alignment.BottomCenter)) {
+            Snackbar(snackbarData = it)
+        }
+    }
+}
+
+/** A row is its own small touch target: tap anywhere in it, not just the
+ * leading control, to select it. */
+private fun Modifier.clickableRow(enabled: Boolean = true, onClick: () -> Unit): Modifier =
+    this.clickable(enabled = enabled, onClick = onClick)
+
+@Composable
+private fun PresetRow(presets: List<SpawnPreset>, selectedPresetId: String, onSelectPreset: (String) -> Unit) {
+    Column(verticalArrangement = Arrangement.spacedBy(4.dp)) {
+        Text("Harness", style = MaterialTheme.typography.labelLarge)
+        Row(
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+            modifier = Modifier.horizontalScroll(rememberScrollState()),
+        ) {
+            for (preset in presets) {
+                val label = if (preset.command.isEmpty()) "Custom…" else preset.label
+                FilterChip(
+                    selected = preset.id == selectedPresetId,
+                    onClick = { onSelectPreset(preset.id) },
+                    label = { Text(label) },
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun ProjectPicker(
+    query: String,
+    onQueryChange: (String) -> Unit,
+    projects: List<Project>,
+    loading: Boolean,
+    selectedPath: String?,
+    homeDir: String,
+    onSelectProject: (Project) -> Unit,
+) {
+    Column(verticalArrangement = Arrangement.spacedBy(4.dp)) {
+        Text("Project", style = MaterialTheme.typography.labelLarge)
+        OutlinedTextField(
+            value = query,
+            onValueChange = onQueryChange,
+            placeholder = { Text("Filter projects…") },
+            singleLine = true,
+            modifier = Modifier.fillMaxWidth(),
+        )
+        when {
+            loading -> Text(
+                "Loading projects…",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            projects.isEmpty() -> Text(
+                "No projects match.",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            else -> LazyColumn(modifier = Modifier.fillMaxWidth().heightIn(max = 220.dp)) {
+                items(projects, key = { it.path }) { project ->
+                    ProjectRow(
+                        project = project,
+                        active = project.path == selectedPath,
+                        homeDir = homeDir,
+                        onClick = { onSelectProject(project) },
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun ProjectRow(project: Project, active: Boolean, homeDir: String, onClick: () -> Unit) {
+    val background = if (active) MaterialTheme.colorScheme.secondaryContainer else MaterialTheme.colorScheme.surface
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clip(MaterialTheme.shapes.small)
+            .background(background)
+            .clickableRow(onClick = onClick)
+            .padding(horizontal = 12.dp, vertical = 8.dp),
+    ) {
+        Text(project.name, style = MaterialTheme.typography.bodyMedium, maxLines = 1, overflow = TextOverflow.Ellipsis)
+        Text(
+            abbreviateHome(parentDir(project.path), homeDir),
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+        )
+    }
+}
+
+private fun abbreviateHome(path: String, homeDir: String): String =
+    if (homeDir.isNotEmpty() && path.startsWith(homeDir)) "~${path.removePrefix(homeDir)}" else path
+
+@Composable
+private fun DirAutocompleteField(
+    cwd: String,
+    suggestions: List<String>,
+    onCwdChange: (String) -> Unit,
+    onPickSuggestion: (String) -> Unit,
+) {
+    Column(verticalArrangement = Arrangement.spacedBy(4.dp)) {
+        OutlinedTextField(
+            value = cwd,
+            onValueChange = onCwdChange,
+            label = { Text("Or type a directory") },
+            placeholder = { Text("/home/user/project") },
+            singleLine = true,
+            modifier = Modifier.fillMaxWidth(),
+        )
+        if (suggestions.isNotEmpty()) {
+            LazyColumn(modifier = Modifier.fillMaxWidth().heightIn(max = 160.dp)) {
+                items(suggestions) { entry ->
+                    Text(
+                        text = "$entry/",
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .clickableRow { onPickSuggestion(entry) }
+                            .padding(horizontal = 12.dp, vertical = 6.dp),
+                        style = MaterialTheme.typography.bodySmall,
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun BranchSection(
+    enabled: Boolean,
+    onEnabledChange: (Boolean) -> Unit,
+    baseRepo: String?,
+    mode: WorktreeBranchMode,
+    onModeChange: (WorktreeBranchMode) -> Unit,
+    newBranch: String,
+    onNewBranchChange: (String) -> Unit,
+    branches: List<BranchInfo>,
+    branchesLoading: Boolean,
+    existingBranch: String,
+    onExistingBranchChange: (String) -> Unit,
+) {
+    Column(verticalArrangement = Arrangement.spacedBy(4.dp)) {
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            Checkbox(checked = enabled, onCheckedChange = onEnabledChange)
+            Text("Create git worktree")
+        }
+        if (!enabled) return@Column
+
+        if (baseRepo == null) {
+            Text(
+                "Choose a directory inside a git repository first.",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            return@Column
+        }
+        Text("repo: $baseRepo", style = MaterialTheme.typography.bodySmall, color = MaterialTheme.colorScheme.onSurfaceVariant)
+
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            RadioButton(selected = mode == WorktreeBranchMode.New, onClick = { onModeChange(WorktreeBranchMode.New) })
+            Text("New branch")
+            Spacer(Modifier.width(16.dp))
+            RadioButton(selected = mode == WorktreeBranchMode.Existing, onClick = { onModeChange(WorktreeBranchMode.Existing) })
+            Text("Existing branch")
+        }
+
+        if (mode == WorktreeBranchMode.New) {
+            OutlinedTextField(
+                value = newBranch,
+                onValueChange = onNewBranchChange,
+                label = { Text("New branch name") },
+                placeholder = { Text("feat/foo") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth(),
+            )
+        } else {
+            when {
+                branchesLoading -> Text(
+                    "Loading branches…",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                branches.isEmpty() -> Text(
+                    "No local branches found.",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                else -> LazyColumn(modifier = Modifier.fillMaxWidth().heightIn(max = 180.dp)) {
+                    items(branches, key = { it.name }) { branch ->
+                        val held = branch.worktree ?: (if (branch.is_head) "the main checkout" else null)
+                        Row(
+                            verticalAlignment = Alignment.CenterVertically,
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .clickableRow(enabled = held == null) { onExistingBranchChange(branch.name) }
+                                .padding(horizontal = 12.dp, vertical = 8.dp),
+                        ) {
+                            RadioButton(
+                                selected = branch.name == existingBranch,
+                                onClick = { onExistingBranchChange(branch.name) },
+                                enabled = held == null,
+                            )
+                            Column {
+                                Text(branch.name, style = MaterialTheme.typography.bodyMedium)
+                                if (held != null) {
+                                    Text(
+                                        "held by $held",
+                                        style = MaterialTheme.typography.bodySmall,
+                                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                                    )
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

android/app/src/main/java/pt/naps/maestro/ui/spawn/SpawnViewModel.kt

@@ -0,0 +1,283 @@
+package pt.naps.maestro.ui.spawn
+
+import java.time.Instant
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import pt.naps.maestro.api.MaestroApiException
+import pt.naps.maestro.api.MaestroClient
+import pt.naps.maestro.data.BranchInfo
+import pt.naps.maestro.data.Project
+import pt.naps.maestro.data.Session
+import pt.naps.maestro.data.SpawnPreset
+
+/** Quiet period after the operator types a raw path before `/api/dirs` and
+ * `/api/gitroot` fire (#269). */
+private const val DIR_AUTOCOMPLETE_DEBOUNCE_MS = 300L
+
+/** Everything above the last segment of an absolute path: `/a/b/c` -> `/a/b`.
+ * A top-level path keeps `/`, and a trailing slash is ignored. Mirrors
+ * `parentDir` in `web/src/paths.ts`. */
+internal fun parentDir(path: String): String {
+    val trimmed = if (path.length > 1 && path.endsWith("/")) path.dropLast(1) else path
+    val slash = trimmed.lastIndexOf('/')
+    return when {
+        slash < 0 -> ""
+        slash == 0 -> "/"
+        else -> trimmed.substring(0, slash)
+    }
+}
+
+/** Splits a path into its directory and trailing (possibly partial) segment.
+ * Mirrors `splitPath` in `web/src/paths.ts`. */
+internal fun splitPath(value: String): Pair<String, String> {
+    val slash = value.lastIndexOf('/')
+    return if (slash == -1) "" to value else value.substring(0, slash + 1) to value.substring(slash + 1)
+}
+
+data class SpawnUiState(
+    val presets: List<SpawnPreset> = FALLBACK_PRESETS,
+    val selectedPresetId: String = "",
+    val customCommand: String = "",
+    val commandTouched: Boolean = false,
+    val structuredView: Boolean = false,
+    val structuredViewTouched: Boolean = false,
+    val homeDir: String = "",
+    val projects: List<Project> = emptyList(),
+    val projectsLoading: Boolean = true,
+    val projectQuery: String = "",
+    val selectedProjectPath: String? = null,
+    val cwd: String = "",
+    val dirSuggestions: List<String> = emptyList(),
+    val baseRepo: String? = null,
+    val worktreeEnabled: Boolean = false,
+    val branchMode: WorktreeBranchMode = WorktreeBranchMode.New,
+    val newBranch: String = "",
+    val existingBranch: String = "",
+    val branches: List<BranchInfo> = emptyList(),
+    val branchesLoading: Boolean = false,
+    val name: String = "",
+    val submitting: Boolean = false,
+    val error: String? = null,
+) {
+    val activePreset: SpawnPreset? get() = presets.find { it.id == selectedPresetId }
+    val isCustomSelected: Boolean get() = activePreset == null || activePreset?.command == ""
+    val command: String get() = if (isCustomSelected) customCommand.trim() else activePreset?.command.orEmpty()
+
+    val visibleProjects: List<Project>
+        get() {
+            val query = projectQuery.trim().lowercase()
+            val filtered = if (query.isEmpty()) {
+                projects
+            } else {
+                projects.filter { it.name.lowercase().contains(query) || it.path.lowercase().contains(query) }
+            }
+            return filtered.sortedByDescending { runCatching { Instant.parse(it.last_activity) }.getOrNull() }
+        }
+
+    val effectiveExistingBranch: String
+        get() = existingBranch.ifEmpty {
+            branches.firstOrNull { it.worktree == null && !it.is_head }?.name.orEmpty()
+        }
+}
+
+/**
+ * Form state and API calls behind [SpawnSheet]. A plain class rather than an
+ * `androidx.lifecycle.ViewModel` — the sheet's own `remember` scope is enough
+ * for a short-lived form, and this keeps the class trivially testable with a
+ * `TestScope`, the same shape as [pt.naps.maestro.connection.DaemonLink].
+ */
+class SpawnViewModel(
+    private val client: MaestroClient,
+    private val scope: CoroutineScope = CoroutineScope(SupervisorJob() + Dispatchers.IO),
+) {
+    private val _state = MutableStateFlow(SpawnUiState())
+    val state: StateFlow<SpawnUiState> = _state.asStateFlow()
+
+    private var dirJob: Job? = null
+    private var branchesJob: Job? = null
+
+    init {
+        scope.launch {
+            val info = runCatching { client.getDaemonInfo() }.getOrNull()
+            _state.update { s ->
+                val presets = info?.presets?.takeIf { it.isNotEmpty() } ?: FALLBACK_PRESETS
+                val seeded = if (!s.commandTouched && s.selectedPresetId.isEmpty()) {
+                    presets.firstOrNull { it.command.isNotEmpty() }?.id ?: s.selectedPresetId
+                } else {
+                    s.selectedPresetId
+                }
+                s.copy(homeDir = info?.home_dir.orEmpty(), presets = presets, selectedPresetId = seeded)
+                    .withSyncedStructuredView()
+            }
+        }
+        scope.launch {
+            val projects = runCatching { client.listProjects() }.getOrDefault(emptyList())
+            _state.update { it.copy(projects = projects, projectsLoading = false) }
+        }
+    }
+
+    fun selectPreset(id: String) {
+        _state.update { it.copy(selectedPresetId = id, commandTouched = true).withSyncedStructuredView() }
+    }
+
+    fun setCustomCommand(text: String) {
+        _state.update { it.copy(customCommand = text, commandTouched = true).withSyncedStructuredView() }
+    }
+
+    fun setStructuredView(enabled: Boolean) {
+        _state.update { it.copy(structuredView = enabled, structuredViewTouched = true) }
+    }
+
+    /** Re-derives the structured-view checkbox from the command this state
+     * carries, unless the operator has already ticked/unticked it by hand. */
+    private fun SpawnUiState.withSyncedStructuredView(): SpawnUiState =
+        if (structuredViewTouched) this else copy(structuredView = supportsStructuredView(command))
+
+    fun setProjectQuery(query: String) {
+        _state.update { it.copy(projectQuery = query) }
+    }
+
+    fun selectProject(project: Project) {
+        dirJob?.cancel()
+        _state.update {
+            it.copy(
+                selectedProjectPath = project.path,
+                cwd = project.path,
+                dirSuggestions = emptyList(),
+                baseRepo = project.base_repo ?: project.path,
+                branches = emptyList(),
+                existingBranch = "",
+            )
+        }
+    }
+
+    /** The operator typed a path by hand: clears any project pick, and
+     * schedules a debounced refresh of both the directory-suggestion
+     * dropdown and the git-root probe that resolves [SpawnUiState.baseRepo]. */
+    fun setCwd(raw: String) {
+        _state.update {
+            it.copy(
+                cwd = raw,
+                selectedProjectPath = null,
+                baseRepo = null,
+                branches = emptyList(),
+                existingBranch = "",
+            )
+        }
+        dirJob?.cancel()
+        dirJob = scope.launch {
+            delay(DIR_AUTOCOMPLETE_DEBOUNCE_MS)
+            refreshDirSuggestions(raw)
+            refreshBaseRepo(raw)
+        }
+    }
+
+    /** Appends [entry] as the next path segment, matching the `cd dir/sub`
+     * drill-in gesture the web `DirAutocomplete` uses. */
+    fun pickDirSuggestion(entry: String) {
+        val (dir, _) = splitPath(_state.value.cwd)
+        setCwd("$dir$entry/")
+    }
+
+    private suspend fun refreshDirSuggestions(raw: String) {
+        val (dir, prefix) = splitPath(raw)
+        val entries = runCatching { client.listDir(dir).entries }.getOrDefault(emptyList())
+        if (_state.value.cwd != raw) return // a newer edit superseded this one
+        val filtered = entries.filter { it.startsWith(prefix, ignoreCase = true) }
+        _state.update { it.copy(dirSuggestions = filtered) }
+    }
+
+    private suspend fun refreshBaseRepo(raw: String) {
+        val root = runCatching { client.gitRoot(raw).root }.getOrNull()
+        if (_state.value.cwd != raw) return // a newer edit superseded this one
+        _state.update { it.copy(baseRepo = root) }
+    }
+
+    fun setWorktreeEnabled(enabled: Boolean) {
+        _state.update { it.copy(worktreeEnabled = enabled) }
+    }
+
+    fun setBranchMode(mode: WorktreeBranchMode) {
+        _state.update { it.copy(branchMode = mode) }
+        if (mode == WorktreeBranchMode.Existing) loadBranchesIfNeeded()
+    }
+
+    fun setNewBranch(text: String) {
+        _state.update { it.copy(newBranch = text) }
+    }
+
+    fun setExistingBranch(text: String) {
+        _state.update { it.copy(existingBranch = text) }
+    }
+
+    private fun loadBranchesIfNeeded() {
+        val cwd = _state.value.cwd
+        if (cwd.isEmpty() || _state.value.branchesLoading) return
+        branchesJob?.cancel()
+        _state.update { it.copy(branchesLoading = true) }
+        branchesJob = scope.launch {
+            val branches = runCatching { client.listBranches(cwd) }.getOrDefault(emptyList())
+            if (_state.value.cwd != cwd) return@launch // a newer cwd superseded this fetch
+            _state.update { it.copy(branches = branches, branchesLoading = false) }
+        }
+    }
+
+    fun setName(text: String) {
+        _state.update { it.copy(name = text) }
+    }
+
+    /** `GET /api/names?count=1`: replaces the session-name field with a
+     * freshly generated handle. */
+    fun rerollName() {
+        scope.launch {
+            val handle = runCatching { client.fetchNames(1).names.firstOrNull() }.getOrNull()
+            if (handle != null) _state.update { it.copy(name = handle) }
+        }
+    }
+
+    /** Validates the form, `POST`s it, and calls [onSuccess] with the new
+     * session. Any failure — validation or API — lands in
+     * [SpawnUiState.error] instead. */
+    fun submit(onSuccess: (Session) -> Unit) {
+        val s = _state.value
+        val values = SpawnFormValues(
+            command = s.command,
+            cwd = s.cwd,
+            name = s.name,
+            structuredView = s.structuredView,
+            autoApprove = s.activePreset?.auto_approve ?: false,
+            worktreeEnabled = s.worktreeEnabled,
+            worktreeBranch = if (s.branchMode == WorktreeBranchMode.Existing) s.effectiveExistingBranch else s.newBranch,
+            worktreeBranchMode = s.branchMode,
+        )
+        when (val built = buildSpawnRequest(values, s.baseRepo)) {
+            is SpawnBuildResult.Error -> _state.update { it.copy(error = built.message) }
+            is SpawnBuildResult.Ok -> {
+                _state.update { it.copy(submitting = true, error = null) }
+                scope.launch {
+                    try {
+                        val session = client.createSession(built.request)
+                        _state.update { it.copy(submitting = false) }
+                        onSuccess(session)
+                    } catch (e: MaestroApiException) {
+                        _state.update { it.copy(submitting = false, error = e.message ?: e.detail) }
+                    } catch (e: Exception) {
+                        _state.update { it.copy(submitting = false, error = e.message ?: "Failed to spawn session.") }
+                    }
+                }
+            }
+        }
+    }
+
+    fun dismissError() {
+        _state.update { it.copy(error = null) }
+    }
+}

android/app/src/test/java/pt/naps/maestro/ui/sidebar/SessionFormattingTest.kt

@@ -0,0 +1,190 @@
+package pt.naps.maestro.ui.sidebar
+
+import kotlinx.serialization.json.JsonPrimitive
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import pt.naps.maestro.data.InTheWay
+import pt.naps.maestro.data.Session
+import pt.naps.maestro.data.SessionStatus
+import pt.naps.maestro.data.SessionWorktree
+
+private fun session(
+    command: String = "claude",
+    cwd: String = "/home/user/project",
+    metadata: Map<String, JsonPrimitive> = emptyMap(),
+    worktree: SessionWorktree? = null,
+    blockedWork: InTheWay? = null,
+    activitySince: String = "1970-01-01T00:00:00Z",
+) = Session(
+    id = "s1",
+    cwd = cwd,
+    command = command,
+    metadata = metadata,
+    worktree = worktree,
+    status = SessionStatus.Running,
+    created_at = "2026-01-01T00:00:00Z",
+    blocked_work = blockedWork,
+    activity_since = activitySince,
+)
+
+class DurationFormattingTest {
+    @Test
+    fun `floors seconds under a minute`() {
+        assertEquals("30s", activityDurationLabel(30_000))
+        assertEquals("59s", activityDurationLabel(59_999))
+    }
+
+    @Test
+    fun `floors minutes under an hour`() {
+        assertEquals("4m", activityDurationLabel(4 * 60_000 + 59_000))
+    }
+
+    @Test
+    fun `floors hours with no days unit`() {
+        assertEquals("2h", activityDurationLabel(2 * 3_600_000 + 59 * 60_000))
+    }
+
+    @Test
+    fun `held ms is null for missing or implausible since`() {
+        assertNull(activityHeldMs(null, 1_000))
+        assertNull(activityHeldMs("", 1_000))
+        assertNull(activityHeldMs("1970-01-01T00:00:00Z", 1_000))
+        assertNull(activityHeldMs("not-a-timestamp", 1_000))
+    }
+
+    @Test
+    fun `held ms is the gap to now for a plausible timestamp`() {
+        val since = "2026-01-01T00:00:00Z"
+        val nowMs = java.time.Instant.parse("2026-01-01T00:00:31Z").toEpochMilli()
+        assertEquals(31_000L, activityHeldMs(since, nowMs))
+    }
+}
+
+class SessionNameTest {
+    @Test
+    fun `falls back to the command when no name is set`() {
+        assertEquals("claude --resume", sessionName(session(command = "claude --resume")))
+    }
+
+    @Test
+    fun `uses the custom name when set`() {
+        val s = session(metadata = mapOf("name" to JsonPrimitive("api-work")))
+        assertEquals("api-work", sessionName(s))
+    }
+
+    @Test
+    fun `an empty stored name is treated as unset`() {
+        val s = session(metadata = mapOf("name" to JsonPrimitive("")))
+        assertNull(customSessionName(s))
+    }
+
+    @Test
+    fun `generated name is provisional, user and haiku are not`() {
+        val generated = session(
+            metadata = mapOf(
+                "name" to JsonPrimitive("brave-otter"),
+                "name_source" to JsonPrimitive("Generated"),
+            ),
+        )
+        val user = session(
+            metadata = mapOf(
+                "name" to JsonPrimitive("api-work"),
+                "name_source" to JsonPrimitive("User"),
+            ),
+        )
+        val unknownSource = session(
+            metadata = mapOf(
+                "name" to JsonPrimitive("api-work"),
+                "name_source" to JsonPrimitive("something-new"),
+            ),
+        )
+        assertTrue(isProvisionalName(generated))
+        assertFalse(isProvisionalName(user))
+        assertFalse(isProvisionalName(unknownSource))
+    }
+}
+
+class BlockerStatsTest {
+    @Test
+    fun `renders insertions and deletions in diff notation`() {
+        val w = InTheWay(uncommitted_files = 2, untracked_files = 3, unpushed_commits = 2, insertions = 124, deletions = 18)
+        val stats = blockerStats(w).associate { it.kind to it.text }
+        assertEquals("+124", stats["add"])
+        assertEquals("-18", stats["del"])
+        assertEquals("?3", stats["untracked"])
+        assertEquals("↑2", stats["unpushed"])
+        assertNull(stats["files"])
+    }
+
+    @Test
+    fun `falls back to a file count when a tracked change carries no line delta`() {
+        val w = InTheWay(uncommitted_files = 2, insertions = 0, deletions = 0)
+        val stats = blockerStats(w)
+        assertEquals(listOf(BlockerStat("files", "~2")), stats)
+    }
+
+    @Test
+    fun `session blockers are null when nothing blocks a kill`() {
+        assertNull(sessionBlockers(session(blockedWork = null)))
+        assertNull(sessionBlockers(session(blockedWork = InTheWay())))
+    }
+
+    @Test
+    fun `format in the way spells out zero as no unsaved work`() {
+        assertEquals("no unsaved work", formatInTheWay(InTheWay()))
+        assertEquals("1 uncommitted file, 2 untracked files", formatInTheWay(InTheWay(uncommitted_files = 1, untracked_files = 2)))
+    }
+}
+
+class ProgramNameTest {
+    @Test
+    fun `drops arguments and basenames the path`() {
+        assertEquals("claude", programName("/usr/local/bin/claude -p hi"))
+        assertEquals("claude", programName("claude --dangerously-skip-permissions"))
+    }
+
+    @Test
+    fun `looks through leading env assignments`() {
+        assertEquals("claude", programName("FOO=bar BAZ=qux claude --resume"))
+    }
+
+    @Test
+    fun `looks through sudo and env wrappers with their own flags`() {
+        assertEquals("claude", programName("sudo claude"))
+        assertEquals("claude", programName("env -i FOO=bar claude"))
+    }
+
+    @Test
+    fun `looks through js-toolchain launchers`() {
+        assertEquals("claude-code", programName("npx claude-code"))
+        assertEquals("claude", programName("pnpm dlx claude"))
+        assertEquals("claude", programName("bunx claude"))
+    }
+
+    @Test
+    fun `a command that is nothing but wrappers is shown as written`() {
+        assertEquals("sudo", programName("sudo"))
+    }
+}
+
+class GroupingTest {
+    @Test
+    fun `groups by worktree base_repo when present`() {
+        val a = session(cwd = "/wt/a", worktree = SessionWorktree(path = "/wt/a", base_repo = "/home/user/maestro"))
+        val b = session(cwd = "/wt/b", worktree = SessionWorktree(path = "/wt/b", base_repo = "/home/user/maestro"))
+        val groups = groupSessions(listOf(a, b))
+        assertEquals(1, groups.size)
+        assertEquals("maestro", groups.single().label)
+        assertEquals(2, groups.single().sessions.size)
+    }
+
+    @Test
+    fun `falls back to cwd with no worktree`() {
+        val a = session(cwd = "/home/user/scratch")
+        val groups = groupSessions(listOf(a))
+        assertEquals("scratch", groups.single().label)
+    }
+}

android/app/src/test/java/pt/naps/maestro/ui/spawn/SpawnModelTest.kt

@@ -0,0 +1,107 @@
+package pt.naps.maestro.ui.spawn
+
+import kotlinx.serialization.json.JsonPrimitive
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import pt.naps.maestro.data.SessionView
+
+private val base = SpawnFormValues(
+    command = "claude",
+    cwd = "/home/user/project",
+    name = "amber-fox",
+    structuredView = false,
+    autoApprove = false,
+    worktreeEnabled = false,
+    worktreeBranch = "",
+    worktreeBranchMode = WorktreeBranchMode.New,
+)
+
+class SpawnModelTest {
+    @Test
+    fun `builds a plain request with the picked cwd and command`() {
+        val result = buildSpawnRequest(base, null) as SpawnBuildResult.Ok
+        assertEquals("/home/user/project", result.request.cwd)
+        assertEquals("claude", result.request.command)
+        assertEquals(mapOf("name" to JsonPrimitive("amber-fox")), result.request.metadata)
+        assertEquals(SessionView.Terminal, result.request.view)
+    }
+
+    @Test
+    fun `omits metadata name when the name is blank`() {
+        val result = buildSpawnRequest(base.copy(name = "   "), null) as SpawnBuildResult.Ok
+        assertTrue(result.request.metadata.isEmpty())
+    }
+
+    @Test
+    fun `requests structured view for resolved claude and codex commands`() {
+        for (command in listOf("claude", "FOO=1 codex", "env -i codex")) {
+            val result = buildSpawnRequest(base.copy(command = command, structuredView = true), null) as SpawnBuildResult.Ok
+            assertEquals("expected structured view for `$command`", SessionView.Structured, result.request.view)
+        }
+    }
+
+    @Test
+    fun `does not request structured view for unsupported commands`() {
+        val result = buildSpawnRequest(base.copy(command = "zsh", structuredView = true), null) as SpawnBuildResult.Ok
+        assertEquals(SessionView.Terminal, result.request.view)
+    }
+
+    @Test
+    fun `attaches a trimmed branch when worktree is enabled`() {
+        val result = buildSpawnRequest(
+            base.copy(worktreeEnabled = true, worktreeBranch = "  feat/foo  "),
+            "/home/user/project",
+        ) as SpawnBuildResult.Ok
+        assertEquals("/home/user/project", result.request.worktree?.base_repo)
+        assertEquals("feat/foo", result.request.worktree?.branch)
+        assertTrue(result.request.worktree?.create_branch == true)
+    }
+
+    @Test
+    fun `checks out an existing branch when the mode is existing`() {
+        val result = buildSpawnRequest(
+            base.copy(worktreeEnabled = true, worktreeBranch = "spawn-v2", worktreeBranchMode = WorktreeBranchMode.Existing),
+            "/home/user/project",
+        ) as SpawnBuildResult.Ok
+        assertEquals(false, result.request.worktree?.create_branch)
+    }
+
+    @Test
+    fun `rejects an existing-mode worktree with no branch picked`() {
+        val result = buildSpawnRequest(
+            base.copy(worktreeEnabled = true, worktreeBranch = "", worktreeBranchMode = WorktreeBranchMode.Existing),
+            "/repo",
+        )
+        assertTrue(result is SpawnBuildResult.Error)
+    }
+
+    @Test
+    fun `rejects a missing working directory`() {
+        assertTrue(buildSpawnRequest(base.copy(cwd = ""), null) is SpawnBuildResult.Error)
+    }
+
+    @Test
+    fun `rejects a missing command`() {
+        assertTrue(buildSpawnRequest(base.copy(command = ""), null) is SpawnBuildResult.Error)
+    }
+
+    @Test
+    fun `rejects a worktree without an inferred base repo`() {
+        val result = buildSpawnRequest(base.copy(worktreeEnabled = true, worktreeBranch = "b"), null)
+        assertTrue(result is SpawnBuildResult.Error)
+    }
+
+    @Test
+    fun `rejects a worktree without a branch name`() {
+        val result = buildSpawnRequest(base.copy(worktreeEnabled = true, worktreeBranch = "  "), "/repo")
+        assertTrue(result is SpawnBuildResult.Error)
+    }
+
+    @Test
+    fun `resolveProgram strips env assignments and paths`() {
+        assertEquals("codex", resolveProgram("FOO=1 /usr/local/bin/codex --flag"))
+        assertEquals("claude", resolveProgram("claude"))
+        assertEquals("zsh", resolveProgram("zsh -l"))
+    }
+}

android/app/src/test/java/pt/naps/maestro/ui/spawn/SpawnViewModelTest.kt

@@ -0,0 +1,237 @@
+package pt.naps.maestro.ui.spawn
+
+import app.cash.turbine.test
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.ConcurrentLinkedQueue
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.runBlocking
+import okhttp3.mockwebserver.Dispatcher
+import okhttp3.mockwebserver.MockResponse
+import okhttp3.mockwebserver.MockWebServer
+import okhttp3.mockwebserver.RecordedRequest
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+import pt.naps.maestro.api.MaestroClient
+import pt.naps.maestro.data.Project
+
+/** Routes each enqueued response by request path rather than arrival order —
+ * [SpawnViewModel]'s init fires `/api/info` and `/api/projects` concurrently,
+ * so a plain FIFO queue can hand either endpoint the other's response. */
+private class RoutedDispatcher : Dispatcher() {
+    private val queues = ConcurrentHashMap<String, ConcurrentLinkedQueue<MockResponse>>()
+
+    fun enqueue(path: String, response: MockResponse) {
+        queues.getOrPut(path) { ConcurrentLinkedQueue() }.add(response)
+    }
+
+    override fun dispatch(request: RecordedRequest): MockResponse {
+        val path = request.path.orEmpty().substringBefore('?')
+        return queues[path]?.poll() ?: MockResponse().setResponseCode(404)
+    }
+}
+
+class SpawnViewModelTest {
+    private lateinit var server: MockWebServer
+    private lateinit var dispatcher: RoutedDispatcher
+    private lateinit var client: MaestroClient
+    private lateinit var scope: CoroutineScope
+
+    @Before
+    fun setUp() {
+        dispatcher = RoutedDispatcher()
+        server = MockWebServer()
+        server.dispatcher = dispatcher
+        server.start()
+        client = MaestroClient(server.url("/").toString())
+        scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+    }
+
+    @After
+    fun tearDown() {
+        scope.cancel()
+        server.shutdown()
+    }
+
+    private fun jsonResponse(body: String) =
+        MockResponse().setHeader("Content-Type", "application/json").setBody(body)
+
+    /** Enqueues a passing `/api/info` and an empty `/api/projects`, the pair
+     * every test needs before it can observe anything past init. */
+    private fun enqueueInit(infoBody: String = """{"hostname":"h","version":"1","home_dir":"","presets":[],"instance":"i"}""") {
+        dispatcher.enqueue("/api/info", jsonResponse(infoBody))
+        dispatcher.enqueue("/api/projects", jsonResponse("[]"))
+    }
+
+    private fun newViewModel() = SpawnViewModel(client, scope)
+
+    private suspend fun SpawnViewModel.awaitState(predicate: (SpawnUiState) -> Boolean): SpawnUiState {
+        var result: SpawnUiState? = null
+        state.test {
+            var item = awaitItem()
+            while (!predicate(item)) item = awaitItem()
+            result = item
+            cancelAndIgnoreRemainingEvents()
+        }
+        return result ?: error("state predicate never satisfied")
+    }
+
+    @Test
+    fun `loads presets from daemon info and defaults to the first one`() = runBlocking {
+        enqueueInit(
+            """{"hostname":"h","version":"1","home_dir":"/home/x","presets":[
+                {"id":"claude","label":"Claude","command":"claude"},
+                {"id":"custom","label":"Custom…","command":""}
+            ],"instance":"i"}""",
+        )
+
+        val vm = newViewModel()
+        val settled = vm.awaitState { it.selectedPresetId == "claude" }
+
+        assertEquals("claude", settled.command)
+        assertTrue("structured view should auto-tick for claude", settled.structuredView)
+        assertEquals("/home/x", settled.homeDir)
+    }
+
+    @Test
+    fun `falls back to built-in presets when daemon info fails`() = runBlocking {
+        dispatcher.enqueue("/api/info", MockResponse().setResponseCode(500))
+        dispatcher.enqueue("/api/projects", jsonResponse("[]"))
+
+        val vm = newViewModel()
+        val settled = vm.awaitState { it.selectedPresetId.isNotEmpty() }
+
+        assertEquals(FALLBACK_PRESETS, settled.presets)
+    }
+
+    @Test
+    fun `selecting a preset updates the command and structured view`() = runBlocking {
+        enqueueInit()
+        val vm = newViewModel()
+        vm.awaitState { it.selectedPresetId.isNotEmpty() } // let init settle on "claude"
+
+        vm.selectPreset("zsh")
+        val afterZsh = vm.awaitState { it.selectedPresetId == "zsh" }
+        assertEquals("zsh", afterZsh.command)
+        assertTrue("zsh has no structured view", !afterZsh.structuredView)
+
+        vm.selectPreset("claude")
+        val afterClaude = vm.awaitState { it.selectedPresetId == "claude" }
+        assertTrue(afterClaude.structuredView)
+    }
+
+    @Test
+    fun `manual structured view toggle survives a later preset change`() = runBlocking {
+        enqueueInit()
+        val vm = newViewModel()
+        vm.awaitState { it.selectedPresetId == "claude" }
+
+        vm.setStructuredView(false)
+        vm.selectPreset("codex")
+        val after = vm.awaitState { it.selectedPresetId == "codex" }
+        assertTrue("operator's untick should stick", !after.structuredView)
+    }
+
+    @Test
+    fun `selecting a project fills cwd and base repo`() = runBlocking {
+        enqueueInit()
+        val vm = newViewModel()
+        vm.awaitState { !it.projectsLoading }
+
+        vm.selectProject(Project(path = "/repo", name = "repo"))
+        val after = vm.awaitState { it.cwd == "/repo" }
+        assertEquals("/repo", after.baseRepo)
+        assertEquals("/repo", after.selectedProjectPath)
+    }
+
+    @Test
+    fun `typing a raw path debounces dir suggestions and base repo`() = runBlocking {
+        enqueueInit()
+        val vm = newViewModel()
+        vm.awaitState { !it.projectsLoading }
+
+        dispatcher.enqueue("/api/dirs", jsonResponse("""{"path":"/home/user","entries":["proj-a","proj-b"]}"""))
+        dispatcher.enqueue("/api/gitroot", jsonResponse("""{"root":"/home/user/proj-a"}"""))
+
+        vm.setCwd("/home/user/pro")
+        val settled = vm.awaitState { it.dirSuggestions.isNotEmpty() }
+        assertEquals(listOf("proj-a", "proj-b"), settled.dirSuggestions)
+        val withRepo = vm.awaitState { it.baseRepo != null }
+        assertEquals("/home/user/proj-a", withRepo.baseRepo)
+    }
+
+    @Test
+    fun `reroll fills the name field from the daemon`() = runBlocking {
+        enqueueInit()
+        val vm = newViewModel()
+        vm.awaitState { !it.projectsLoading }
+
+        dispatcher.enqueue("/api/names", jsonResponse("""{"names":["amber-fox"]}"""))
+        vm.rerollName()
+        val after = vm.awaitState { it.name == "amber-fox" }
+        assertEquals("amber-fox", after.name)
+    }
+
+    @Test
+    fun `submit rejects a missing working directory without a network call`() = runBlocking {
+        enqueueInit()
+        val vm = newViewModel()
+        vm.awaitState { it.selectedPresetId == "claude" }
+
+        var succeeded = false
+        vm.submit { succeeded = true }
+        val after = vm.awaitState { it.error != null }
+        assertNotNull(after.error)
+        assertTrue(!succeeded)
+    }
+
+    @Test
+    fun `submit posts the built request and reports the new session`() = runBlocking {
+        enqueueInit()
+        val vm = newViewModel()
+        vm.awaitState { it.selectedPresetId == "claude" }
+        vm.selectProject(Project(path = "/repo", name = "repo"))
+        vm.awaitState { it.cwd == "/repo" }
+
+        dispatcher.enqueue(
+            "/api/sessions",
+            jsonResponse(
+                """{"id":"s1","cwd":"/repo","command":"claude","status":"Running","created_at":"2026-01-01T00:00:00Z"}""",
+            ),
+        )
+        var result: pt.naps.maestro.data.Session? = null
+        vm.submit { result = it }
+        val after = vm.awaitState { !it.submitting && it.error == null }
+        assertNull(after.error)
+        assertEquals("s1", result?.id)
+
+        var request = server.takeRequest()
+        while (request.method != "POST") request = server.takeRequest()
+        assertEquals("/api/sessions", request.path)
+    }
+
+    @Test
+    fun `submit surfaces the daemon's error detail on failure`() = runBlocking {
+        enqueueInit()
+        val vm = newViewModel()
+        vm.awaitState { it.selectedPresetId == "claude" }
+        vm.selectProject(Project(path = "/repo", name = "repo"))
+        vm.awaitState { it.cwd == "/repo" }
+
+        dispatcher.enqueue(
+            "/api/sessions",
+            MockResponse().setResponseCode(400).setHeader("Content-Type", "application/json")
+                .setBody("""{"error":{"code":"bad_request","message":"cwd does not exist"}}"""),
+        )
+        vm.submit {}
+        val after = vm.awaitState { it.error != null }
+        assertTrue(after.error!!.contains("cwd does not exist"))
+    }
+}

android/gradle/libs.versions.toml

@@ -9,6 +9,7 @@ navigationCompose = "2.8.2"
 okhttp = "4.12.0"
 kotlinxSerializationJson = "1.7.3"
 kotlinxCoroutines = "1.9.0"
+turbine = "1.1.0"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -27,6 +28,9 @@ androidx-navigation-compose = { group = "androidx.navigation", name = "navigatio
 okhttp = { group = "com.squareup.okhttp3", name = "okhttp", version.ref = "okhttp" }
 kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "kotlinxSerializationJson" }
 kotlinx-coroutines-android = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-android", version.ref = "kotlinxCoroutines" }
+kotlinx-coroutines-test = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-test", version.ref = "kotlinxCoroutines" }
+okhttp-mockwebserver = { group = "com.squareup.okhttp3", name = "mockwebserver", version.ref = "okhttp" }
+turbine = { group = "app.cash.turbine", name = "turbine", version.ref = "turbine" }
 junit = { group = "junit", name = "junit", version = "4.13.2" }
 androidx-test-ext-junit = { group = "androidx.test.ext", name = "junit", version = "1.2.1" }
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version = "3.6.1" }