feat(maestro): force-kill prompt in the web client

The kill button now sends the unforced DELETE immediately instead of
asking first. Only the daemon's guard refusal raises a prompt, and it is
a real dialog rather than confirm(), so it can offer the override the
daemon already implements.

The API error envelope is decoded into ApiRequestError, keeping the code
and the unsaved-work breakdown so the dialog names what is in the way.

crates/maestro-protocol/src/display.rs

@@ -140,6 +140,63 @@ pub fn merge_linear<T>(folder: TreeFolder<T>) -> TreeFolder<T> {
     cur
 }
 
+/// Command wrappers that run another program: the program is what follows.
+const WRAPPERS: [&str; 8] = [
+    "sudo", "env", "npx", "bunx", "uvx", "pnpm", "yarn", "command",
+];
+
+/// The program a command line runs, basenamed and stripped of its arguments —
+/// what a session card shows per `docs/SIDEBAR.md`, which names the program
+/// and never its flags. Leading `FOO=bar` assignments and wrappers (`sudo`,
+/// `npx`, `pnpm dlx`, …) are looked through. Mirrors the web's `splitCommand`.
+pub fn command_program(command: &str) -> String {
+    let words: Vec<&str> = command.split_whitespace().collect();
+    let mut i = 0;
+    while i < words.len() {
+        let word = words[i];
+        if is_env_assignment(word) {
+            i += 1;
+            continue;
+        }
+        let wrapper = basename(word).to_lowercase();
+        if WRAPPERS.contains(&wrapper.as_str()) {
+            i += 1;
+            if (wrapper == "pnpm" || wrapper == "yarn") && words.get(i) == Some(&"dlx") {
+                i += 1;
+            }
+            continue;
+        }
+        break;
+    }
+    match words.get(i) {
+        Some(word) => basename(word).to_string(),
+        // Nothing but wrappers and assignments: say what was there rather than
+        // rendering an empty fragment.
+        None => command.trim().to_string(),
+    }
+}
+
+/// `FOO=bar`, the shell's own prefix for one command's environment.
+fn is_env_assignment(word: &str) -> bool {
+    let mut chars = word.chars();
+    match chars.next() {
+        Some(c) if c.is_ascii_alphabetic() || c == '_' => {}
+        _ => return false,
+    }
+    let rest: String = chars.collect();
+    match rest.split_once('=') {
+        Some((name, _)) => name.chars().all(|c| c.is_ascii_alphanumeric() || c == '_'),
+        None => false,
+    }
+}
+
+fn basename(word: &str) -> &str {
+    match word.rsplit_once('/') {
+        Some((_, tail)) => tail,
+        None => word,
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -318,4 +375,28 @@ mod tests {
         };
         assert_eq!(nested.name, "a/b");
     }
+
+    #[test]
+    fn command_program_drops_arguments() {
+        assert_eq!(
+            command_program("claude --dangerously-skip-permissions"),
+            "claude"
+        );
+        assert_eq!(command_program("  zsh   -l  "), "zsh");
+        assert_eq!(command_program("hx src/main.rs"), "hx");
+    }
+
+    #[test]
+    fn command_program_looks_through_paths_env_and_wrappers() {
+        assert_eq!(command_program("/usr/local/bin/claude -p hi"), "claude");
+        assert_eq!(command_program("FOO=1 BAR=2 claude"), "claude");
+        assert_eq!(command_program("npx opencode"), "opencode");
+        assert_eq!(command_program("pnpm dlx opencode run"), "opencode");
+    }
+
+    #[test]
+    fn command_program_keeps_a_line_that_is_only_wrappers() {
+        assert_eq!(command_program("sudo"), "sudo");
+        assert_eq!(command_program(""), "");
+    }
 }

crates/maestro-tui/src/sidebar.rs

@@ -8,7 +8,9 @@ use std::collections::{BTreeMap, HashSet};
 use std::path::PathBuf;
 
 use chrono::Utc;
-use maestro_protocol::display::{abbreviate_dir, abbreviate_folder_name, session_tree_path};
+use maestro_protocol::display::{
+    abbreviate_dir, abbreviate_folder_name, command_program, session_tree_path,
+};
 use maestro_protocol::{ActivityState, Session, SessionStatus, StatKind};
 use ratatui::layout::Rect;
 use ratatui::style::{Color, Modifier, Style};
@@ -297,7 +299,8 @@ impl Sidebar {
         if dead {
             tail.push(Span::styled(" exited", muted));
         }
-        let command = Span::styled(format!(" {}", s.command), muted);
+        // docs/SIDEBAR.md: the card names the program, never its arguments.
+        let command = Span::styled(format!(" {}", command_program(&s.command)), muted);
 
         // Reserve the triggered status fragments before detail and command.
         // If the row is exceptionally narrow, keep one column for the
@@ -874,12 +877,34 @@ mod tests {
         );
     }
 
+    /// docs/SIDEBAR.md: line 2 names the program, never its arguments.
+    #[test]
+    fn meta_line_drops_the_commands_arguments() {
+        let mut s = session_named(1, "handle");
+        s.command = "claude --dangerously-skip-permissions".into();
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 60, 6));
+        let meta = content(&all[3]);
+        assert!(
+            meta.contains("claude"),
+            "line 2 must name the program: {meta:?}"
+        );
+        assert!(
+            !meta.contains("dangerously"),
+            "line 2 must not carry arguments: {meta:?}"
+        );
+    }
+
     /// The sidebar is narrow: the command truncates with `…` and never wraps
     /// onto a third row (docs/SIDEBAR.md).
     #[test]
     fn meta_line_command_truncates_instead_of_wrapping() {
         let mut s = session_named(1, "claude");
-        s.command = "a command that cannot fit".into();
+        s.command = "a-program-name-that-cannot-fit".into();
         s.activity_since = Utc::now() - Duration::seconds(5);
         s.blocked_work = Some(InTheWay {
             uncommitted_files: 120,
@@ -1099,7 +1124,7 @@ mod tests {
     #[test]
     fn blocked_warning_survives_before_a_truncated_command() {
         let mut s = session_named(1, "name");
-        s.command = "a command that cannot fit".into();
+        s.command = "a-program-name-that-cannot-fit".into();
         s.blocked_work = Some(InTheWay {
             uncommitted_files: 1,
             ..Default::default()

docs/SIDEBAR.md

@@ -88,21 +88,26 @@ of `maestro_protocol::InTheWay`'s `Display` does not disappear: it is the web
 card's tooltip and the wording of the kill refusal, so no two clients describe
 the same tree differently.
 
-`<command>` is unconditional and muted: the session's command line, shown on
+`<command>` is unconditional and muted: it names the **program** the session
-every card in both clients — no omission in the TUI, no name-vs-command
+runs — never its arguments. `claude --dangerously-skip-permissions` renders as
-comparison gating it. A session named by its command line then shows the same
+`claude`. Flags say how a session was invoked, which is not what a card is for,
-string on both lines; that is accepted, the price of a row that never changes
+and a long one crowds out every other fragment on the line. It shows on every
-height.
+card in both clients — no omission in the TUI, no name-vs-command comparison
+gating it. A session named by its program then shows the same string on both
+lines; that is accepted, the price of a row that never changes height.
 
-In the **web client** the command's leading program is replaced by that tool's
+The program is found by looking through a path, leading `FOO=bar` assignments
-icon when it is one we have a mark for — Claude Code, Codex, opencode, Gemini
+and wrappers (`sudo`, `env`, `npx`, `pnpm dlx`, …), then taking the basename:
-CLI, Aider, Cursor, pi, and any shell — and only the remaining words of the
+`/usr/local/bin/claude -p hi` is `claude`. A line that is nothing but wrappers
-command line follow as text. Recognition looks through a path, leading
+is shown as written rather than as an empty fragment.
-`FOO=bar` assignments and wrappers (`sudo`, `env`, `npx`, `pnpm dlx`, …); an
+
-unrecognised program keeps its full text, so the card never shows a mark
+In the **web client** the program is replaced by that tool's icon when it is
-standing for the wrong tool. The full command line stays in the card's tooltip
+one we have a mark for — Claude Code, Codex, opencode, Gemini CLI, Aider,
-either way. The **TUI** keeps the command as text: a terminal cannot be assumed
+Cursor, pi, and any shell — and nothing follows it as text. An unrecognised
-to have a font carrying tool glyphs.
+program keeps its name as text, so the card never shows a mark standing for the
+wrong tool. The full command line, arguments and all, stays in the card's
+tooltip either way. The **TUI** keeps the program as text: a terminal cannot be
+assumed to have a font carrying tool glyphs.
 
 ## Colour per activity state
 

docs/WORKTREES.md

@@ -79,6 +79,11 @@ would have blocked. A tree whose guard is clear never needed the override, so a
 forced kill removes it as usual — force changes what happens to blocked work,
 not ordinary cleanup.
 
+In the web client the kill button sends the unforced `DELETE` straight away —
+there is no pre-confirmation, because the daemon is the one that decides. Only
+the refusal raises a prompt, and that prompt names what is in the way and offers
+"Force kill", which repeats the request with `force=true`.
+
 Ending a session and destroying its work are two separate acts. Maestro only
 performs the first one. Removing a tree it left behind is the operator's own
 `git worktree remove`, chosen while looking at exactly what would be lost.

web/src/api.ts

@@ -1,6 +1,7 @@
 import * as routes from "./routes.js";
 import type {
   ApiError,
+  InTheWay,
   Branches,
   CreateSessionRequest,
   DaemonInfo,
@@ -13,19 +14,38 @@ import type {
   Uuid,
 } from "./types.js";
 
+/** A `/api/*` failure with the daemon's own error envelope kept intact, so a
+ * caller can branch on `code` — the kill guard's `kill_guarded` (#79) — and
+ * render `unsavedWork` rather than re-parsing the message. */
+export class ApiRequestError extends Error {
+  readonly status: number;
+  readonly code: string;
+  readonly detail: string;
+  readonly unsavedWork: InTheWay | null;
+
+  constructor(res: Response, info?: ApiError["error"], text?: string) {
+    const detail = info ? `${info.code}: ${info.message}` : (text ?? "");
+    super(`${res.status} ${res.statusText}${detail ? ` — ${detail}` : ""}`);
+    this.name = "ApiRequestError";
+    this.status = res.status;
+    this.code = info?.code ?? "";
+    this.detail = info?.message ?? text ?? "";
+    this.unsavedWork = info?.unsaved_work ?? null;
+  }
+}
+
 async function jsonOrError<T>(res: Response): Promise<T> {
   if (res.ok) {
     if (res.status === 204) return undefined as unknown as T;
     return (await res.json()) as T;
   }
-  let detail = "";
   try {
     const body = (await res.json()) as ApiError;
-    detail = `${body.error.code}: ${body.error.message}`;
+    throw new ApiRequestError(res, body.error);
-  } catch {
+  } catch (e) {
-    detail = await res.text();
+    if (e instanceof ApiRequestError) throw e;
+    throw new ApiRequestError(res, undefined, await res.text().catch(() => ""));
   }
-  throw new Error(`${res.status} ${res.statusText}${detail ? ` — ${detail}` : ""}`);
 }
 
 export async function listSessions(): Promise<Session[]> {
@@ -57,9 +77,14 @@ export async function renameSession(id: Uuid, name: string): Promise<Session> {
   );
 }
 
-export async function killSession(id: Uuid): Promise<void> {
+/** Kill a session. With `force` (#81) the daemon overrides its refusal over a
+ * worktree holding unsaved work and leaves that worktree on disk. */
+export async function killSession(id: Uuid, force = false): Promise<void> {
+  const url = force
+    ? `${routes.session(id)}?${routes.FORCE_QUERY}=true`
+    : routes.session(id);
   await jsonOrError(
-    await fetch(routes.session(id), {
+    await fetch(url, {
       method: "DELETE",
       credentials: "same-origin",
     }),

web/src/attach.ts

@@ -56,12 +56,13 @@ export interface AttachInfo {
   command: string;
 }
 
-/** Header echoes the sidebar: the command's leading program becomes its tool
+/** Header echoes the sidebar: the program becomes its tool icon when we have a
- * icon when we have a mark for it, remaining words stay as text. */
+ * mark for it and stays as its bare name when we do not. Arguments are
+ * dropped, as on the card. */
 function commandFragment(command: string): string {
-  const { tool, rest } = splitCommand(command);
+  const { tool, program } = splitCommand(command);
   const icon = tool ? toolIconSvg(tool) : null;
-  const text = icon ? rest : command;
+  const text = icon ? "" : program;
   return `<span class="at-cmd">${icon ?? ""}${text ? escapeHtml(text) : ""}</span>`;
 }
 

web/src/catalog.test.ts

@@ -1,5 +1,5 @@
 // @vitest-environment happy-dom
-import { beforeAll, describe, expect, it } from "vitest";
+import { afterEach, beforeAll, describe, expect, it } from "vitest";
 
 import { renderSidebar } from "./catalog.js";
 import type { CatalogListener, CatalogStore } from "./events.js";
@@ -16,6 +16,10 @@ beforeAll(() => {
   window.fetch = () => Promise.reject(new Error("offline"));
 });
 
+afterEach(() => {
+  document.querySelector(".kill-dialog")?.remove();
+});
+
 function session(overrides: Partial<Session>): Session {
   return {
     id: "11111111-2222-3333-4444-555555555555",
@@ -46,6 +50,11 @@ function rowFor(el: HTMLElement, id: string): HTMLElement | null {
   return el.querySelector<HTMLElement>(`[data-session-id="${id}"]`);
 }
 
+/** Let the kill chain's awaits (fetch, its json body) settle. */
+async function flush(): Promise<void> {
+  for (let i = 0; i < 8; i++) await Promise.resolve();
+}
+
 describe("blocked-work indicator (#83)", () => {
   it("marks the row of a blocked session in diff notation", () => {
     const blocked = session({
@@ -89,37 +98,77 @@ describe("blocked-work indicator (#83)", () => {
     expect(rowFor(el, unprobed.id)?.querySelector(".leaf-blocked")).toBeNull();
   });
 
-  it("restates the warning at the kill confirm", async () => {
+  it("kills straight away, without a first confirmation", async () => {
-    const confirmations: string[] = [];
+    const calls: string[] = [];
-    window.confirm = (msg?: string) => {
+    window.fetch = ((url: string, init?: RequestInit) => {
-      confirmations.push(msg ?? "");
+      calls.push(`${init?.method ?? "GET"} ${url}`);
-      return false;
+      return Promise.resolve(new Response(null, { status: 204 }));
-    };
+    }) as typeof fetch;
+    const plain = session({ id: "aaaaaaaa-0000-0000-0000-000000000005" });
+    const el = renderSidebar(storeWith([plain])).el;
+    rowFor(el, plain.id)?.querySelector<HTMLButtonElement>(".leaf-kill")?.click();
+    await flush();
+    expect(calls).toContain(`DELETE /api/sessions/${plain.id}`);
+    expect(document.querySelector(".kill-dialog")).toBeNull();
+  });
+
+  it("offers the override when the daemon refuses a guarded kill", async () => {
+    const calls: string[] = [];
+    window.fetch = ((url: string, init?: RequestInit) => {
+      calls.push(`${init?.method ?? "GET"} ${url}`);
+      if (url.includes("force=true")) return Promise.resolve(new Response(null, { status: 204 }));
+      return Promise.resolve(
+        new Response(
+          JSON.stringify({
+            error: {
+              code: "kill_guarded",
+              message: "worktree has unsaved work",
+              unsaved_work: { untracked_files: 1 },
+            },
+          }),
+          { status: 409, headers: { "content-type": "application/json" } },
+        ),
+      );
+    }) as typeof fetch;
     const blocked = session({
       id: "aaaaaaaa-0000-0000-0000-000000000004",
       command: "bash",
       blocked_work: { untracked_files: 1 },
     });
     const el = renderSidebar(storeWith([blocked])).el;
-    const kill = rowFor(el, blocked.id)?.querySelector<HTMLButtonElement>(".leaf-kill");
+    rowFor(el, blocked.id)?.querySelector<HTMLButtonElement>(".leaf-kill")?.click();
-    kill?.click();
+    await flush();
-    await Promise.resolve();
+    const dialog = document.querySelector(".kill-dialog");
-    expect(confirmations).toHaveLength(1);
+    expect(dialog?.textContent).toContain("1 untracked file");
-    expect(confirmations[0]).toContain("1 untracked file");
+    dialog?.querySelector<HTMLButtonElement>(".kill-dialog-force")?.click();
-    expect(confirmations[0]).toContain("refused unless forced");
+    await flush();
+    expect(calls).toContain(`DELETE /api/sessions/${blocked.id}?force=true`);
+    expect(document.querySelector(".kill-dialog")).toBeNull();
   });
 
-  it("confirms plainly when nothing blocks", async () => {
+  it("closes the override prompt without killing on cancel", async () => {
-    const confirmations: string[] = [];
+    const calls: string[] = [];
-    window.confirm = (msg?: string) => {
+    window.fetch = ((url: string, init?: RequestInit) => {
-      confirmations.push(msg ?? "");
+      calls.push(`${init?.method ?? "GET"} ${url}`);
-      return false;
+      return Promise.resolve(
-    };
+        new Response(
-    const plain = session({ id: "aaaaaaaa-0000-0000-0000-000000000005" });
+          JSON.stringify({
-    const el = renderSidebar(storeWith([plain])).el;
+            error: { code: "kill_guarded", message: "worktree has unsaved work" },
-    rowFor(el, plain.id)?.querySelector<HTMLButtonElement>(".leaf-kill")?.click();
+          }),
-    await Promise.resolve();
+          { status: 409, headers: { "content-type": "application/json" } },
-    expect(confirmations).toEqual(['Kill session "claude"?']);
+        ),
+      );
+    }) as typeof fetch;
+    const blocked = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000006",
+      blocked_work: { unpushed_commits: 2 },
+    });
+    const el = renderSidebar(storeWith([blocked])).el;
+    rowFor(el, blocked.id)?.querySelector<HTMLButtonElement>(".leaf-kill")?.click();
+    await flush();
+    document.querySelector<HTMLButtonElement>(".kill-dialog-cancel")?.click();
+    expect(document.querySelector(".kill-dialog")).toBeNull();
+    expect(calls.filter((c) => c.includes("force=true"))).toHaveLength(0);
   });
 });
 
@@ -209,15 +258,16 @@ describe("session cards (#107)", () => {
     expect(cmd?.querySelector(".leaf-cmd-rest")).toBeNull();
   });
 
-  it("keeps the command's arguments as text beside the icon", () => {
+  it("drops the command's arguments, keeping them in the tooltip", () => {
     const s = session({
       id: "aaaaaaaa-0000-0000-0000-00000000001c",
-      command: "claude --resume",
+      command: "claude --dangerously-skip-permissions",
     });
     const el = renderSidebar(storeWith([s])).el;
     const cmd = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line2 .leaf-cmd");
     expect(cmd?.querySelector(".tool-icon")?.getAttribute("data-tool")).toBe("claude");
-    expect(cmd?.querySelector(".leaf-cmd-rest")?.textContent).toBe("--resume");
+    expect(cmd?.querySelector(".leaf-cmd-rest")).toBeNull();
+    expect(cmd?.getAttribute("title")).toBe("claude --dangerously-skip-permissions");
   });
 
   it("keeps an unknown command as plain text", () => {
@@ -228,7 +278,8 @@ describe("session cards (#107)", () => {
     const el = renderSidebar(storeWith([s])).el;
     const cmd = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line2 .leaf-cmd");
     expect(cmd?.querySelector(".tool-icon")).toBeNull();
-    expect(cmd?.querySelector(".leaf-cmd-rest")?.textContent).toBe("hx src/main.rs");
+    expect(cmd?.querySelector(".leaf-cmd-rest")?.textContent).toBe("hx");
+    expect(cmd?.getAttribute("title")).toBe("hx src/main.rs");
   });
 
   it("maps each activity state to its contract slug", () => {

web/src/catalog.ts

@@ -1,5 +1,6 @@
 import { escapeHtml } from "./html.js";
-import { getDaemonInfo, killSession, renameSession } from "./api.js";
+import { ApiRequestError, getDaemonInfo, killSession, renameSession } from "./api.js";
+import { openForceKillDialog } from "./killDialog.js";
 import { openContextMenu } from "./contextMenu.js";
 import { isTypingTarget, toggleHelp } from "./help.js";
 import { CatalogStore } from "./events.js";
@@ -96,13 +97,14 @@ function blockedFragment(blockers: InTheWay): string {
   return `<span class="card-flag leaf-blocked" title="${escapeHtml(title)}">${stats}</span>`;
 }
 
-/** docs/SIDEBAR.md: the command's leading program becomes its tool icon when
+/** docs/SIDEBAR.md: the card names the program only — arguments never reach
- * we have a mark for it, and only the remaining words stay as text. The full
+ * the card. The program becomes its tool icon when we have a mark for it, and
- * command line stays in the tooltip either way. */
+ * stays as its bare name when we do not. The full command line, arguments and
+ * all, stays in the tooltip either way. */
 function commandFragment(command: string): string {
-  const { tool, rest } = splitCommand(command);
+  const { tool, program } = splitCommand(command);
   const icon = tool ? toolIconSvg(tool) : null;
-  const text = icon ? rest : command;
+  const text = icon ? "" : program;
   return `<span class="card-flag leaf-cmd" title="${escapeHtml(command)}">${icon ?? ""}${text ? `<span class="leaf-cmd-rest">${escapeHtml(text)}</span>` : ""}</span>`;
 }
 
@@ -179,7 +181,7 @@ function renderNode(node: TreeNode, depth: number): HTMLElement {
   killBtn.addEventListener("click", (ev) => {
     ev.preventDefault();
     ev.stopPropagation();
-    void confirmAndKill(s, name);
+    void requestKill(s, name);
   });
   row.addEventListener("contextmenu", (ev) => {
     ev.preventDefault();
@@ -191,22 +193,31 @@ function renderNode(node: TreeNode, depth: number): HTMLElement {
         onSelect: () =>
           document.dispatchEvent(new CustomEvent(SPAWN_SIMILAR_EVENT, { detail: s })),
       },
-      { label: "Kill session", danger: true, onSelect: () => void confirmAndKill(s, name) },
+      { label: "Kill session", danger: true, onSelect: () => void requestKill(s, name) },
     ]);
   });
   return row;
 }
 
-/** #83: the confirm restates the warning at the moment of decision. */
+/**
-async function confirmAndKill(s: Session, name: string): Promise<void> {
+ * Kill on the first click (#81): the daemon is the one that decides whether a
-  const blockers = sessionBlockers(s);
+ * session may go, and it refuses over a worktree holding unsaved work. Only
-  const question = blockers
+ * that refusal is worth a prompt, and it needs one `confirm()` cannot give —
-    ? `Kill session "${name}"? Its worktree still has ${formatInTheWay(blockers)} — the kill will be refused unless forced.`
+ * a forced kill. Anything else surfaces as an alert.
-    : `Kill session "${name}"?`;
+ */
-  if (!confirm(question)) return;
+async function requestKill(s: Session, name: string): Promise<void> {
   try {
     await killSession(s.id);
   } catch (e) {
+    if (e instanceof ApiRequestError && e.code === "kill_guarded") {
+      openForceKillDialog({
+        name,
+        blockers: e.unsavedWork ?? sessionBlockers(s),
+        reason: e.detail,
+        onForce: () => killSession(s.id, true),
+      });
+      return;
+    }
     alert(`Failed to kill: ${(e as Error).message}`);
   }
 }

web/src/killDialog.ts

@@ -0,0 +1,104 @@
+/**
+ * Forced-kill prompt (#81).
+ *
+ * The daemon refuses to kill a session whose worktree still holds uncommitted
+ * or unpushed work. `confirm()` can only ask the same question twice, so the
+ * refusal gets its own dialog: it names what is in the way and offers the
+ * override the daemon's `force=true` already implements. A kill the daemon
+ * accepts never reaches here — there is nothing to warn about.
+ */
+import { formatInTheWay, type InTheWay } from "./types.js";
+
+export interface ForceKillPrompt {
+  /** Session name, as the sidebar shows it. */
+  name: string;
+  /** What the daemon reported in the way, when it reported anything. */
+  blockers: InTheWay | null;
+  /** Message from the daemon's refusal, shown when there is no breakdown. */
+  reason: string;
+  /** Run the forced kill. A rejection is rendered in the dialog, which stays
+   *  open so the override can be retried. */
+  onForce: () => Promise<void>;
+}
+
+let open: { el: HTMLElement; onKeydown: (ev: KeyboardEvent) => void } | null = null;
+
+export function closeForceKillDialog(): void {
+  if (!open) return;
+  window.removeEventListener("keydown", open.onKeydown, true);
+  open.el.remove();
+  open = null;
+}
+
+/** Mount the prompt. Opening while one is up replaces it, so a second refusal
+ *  can never stack two dialogs. */
+export function openForceKillDialog(p: ForceKillPrompt): HTMLElement {
+  closeForceKillDialog();
+
+  const el = document.createElement("div");
+  el.className = "kill-dialog";
+  el.setAttribute("role", "dialog");
+  el.setAttribute("aria-modal", "true");
+  el.setAttribute("aria-label", `Kill ${p.name}`);
+
+  const panel = document.createElement("div");
+  panel.className = "kill-dialog-panel";
+
+  const title = document.createElement("h2");
+  title.className = "kill-dialog-title";
+  title.textContent = `Kill "${p.name}"?`;
+
+  const body = document.createElement("p");
+  body.className = "kill-dialog-body";
+  body.textContent = p.blockers
+    ? `Its worktree still has ${formatInTheWay(p.blockers)}. Forcing the kill removes the session and leaves the worktree on disk.`
+    : `${p.reason} Forcing the kill removes the session and leaves the worktree on disk.`;
+
+  const error = document.createElement("p");
+  error.className = "kill-dialog-error";
+  error.hidden = true;
+
+  const actions = document.createElement("div");
+  actions.className = "kill-dialog-actions";
+  const cancel = document.createElement("button");
+  cancel.type = "button";
+  cancel.className = "btn btn-ghost kill-dialog-cancel";
+  cancel.textContent = "Cancel";
+  cancel.addEventListener("click", closeForceKillDialog);
+  const force = document.createElement("button");
+  force.type = "button";
+  force.className = "btn btn-danger kill-dialog-force";
+  force.textContent = "Force kill";
+  force.addEventListener("click", () => {
+    force.disabled = true;
+    void p
+      .onForce()
+      .then(closeForceKillDialog)
+      .catch((e: unknown) => {
+        force.disabled = false;
+        error.hidden = false;
+        error.textContent = `Failed to kill: ${(e as Error).message}`;
+      });
+  });
+  actions.append(cancel, force);
+
+  panel.append(title, body, error, actions);
+
+  // A press on the scrim cancels; one inside the panel is left alone.
+  el.addEventListener("click", (ev) => {
+    if (!panel.contains(ev.target as Node)) closeForceKillDialog();
+  });
+  el.appendChild(panel);
+  document.body.appendChild(el);
+
+  const onKeydown = (ev: KeyboardEvent): void => {
+    if (ev.key !== "Escape") return;
+    ev.preventDefault();
+    ev.stopPropagation();
+    closeForceKillDialog();
+  };
+  window.addEventListener("keydown", onKeydown, true);
+  open = { el, onKeydown };
+  cancel.focus();
+  return el;
+}

web/src/routes.ts

@@ -18,6 +18,10 @@ export const EVENTS = "/api/events";
 /** Name of the query parameter `DIRS` and `GITROOT` both take. */
 export const PATH_QUERY = "path";
 
+/** Name of the query parameter `DELETE /api/sessions/:id` takes (#81):
+ * `force=true` overrides the kill refusal over a guarded worktree. */
+export const FORCE_QUERY = "force";
+
 /** Name of the query parameter `NAMES` takes. */
 export const COUNT_QUERY = "count";
 

web/src/styles.css

@@ -1058,6 +1058,64 @@ input.leaf-rename:focus {
   border-color: color-mix(in oklab, var(--danger) 40%, transparent);
 }
 
+/* ---------- forced-kill prompt (#81) ---------- */
+.kill-dialog {
+  position: fixed;
+  inset: 0;
+  z-index: var(--z-modal);
+  display: grid;
+  place-items: center;
+  padding: var(--sp-4);
+  background: oklch(0 0 0 / 0.5);
+  backdrop-filter: blur(4px);
+}
+
+.kill-dialog-panel {
+  width: min(400px, 100%);
+  padding: var(--sp-4);
+  background: var(--surface);
+  border: 1px solid var(--border-strong);
+  border-radius: var(--r-3);
+  box-shadow: var(--shadow-2);
+}
+
+.kill-dialog-title {
+  margin: 0 0 var(--sp-2);
+  font-family: var(--font-mono);
+  font-size: var(--fs-15);
+  color: var(--ink);
+}
+
+.kill-dialog-body {
+  margin: 0;
+  color: var(--muted);
+  font-size: var(--fs-13);
+  line-height: 1.5;
+}
+
+.kill-dialog-error {
+  margin: var(--sp-2) 0 0;
+  color: var(--danger);
+  font-size: var(--fs-13);
+}
+
+.kill-dialog-actions {
+  display: flex;
+  justify-content: flex-end;
+  gap: var(--sp-2);
+  margin-top: var(--sp-4);
+}
+
+.btn-danger {
+  color: var(--danger);
+  border-color: color-mix(in oklab, var(--danger) 40%, transparent);
+}
+
+.btn-danger:hover {
+  background: var(--danger-tint);
+  border-color: var(--danger);
+}
+
 /* ---------- empty / loading ---------- */
 
 .empty {

web/src/toolIcon.test.ts

@@ -20,12 +20,12 @@ describe("tool icons on the command fragment (docs/SIDEBAR.md)", () => {
     }
   });
 
-  it("keeps everything after the program as text", () => {
+  it("drops everything after the program", () => {
-    expect(splitCommand("claude --resume -p hi")).toEqual({
+    expect(splitCommand("claude --dangerously-skip-permissions")).toEqual({
       tool: "claude",
-      rest: "--resume -p hi",
+      program: "claude",
     });
-    expect(splitCommand("  zsh   -l  ")).toEqual({ tool: "shell", rest: "-l" });
+    expect(splitCommand("  zsh   -l  ")).toEqual({ tool: "shell", program: "zsh" });
   });
 
   it("looks through paths, env assignments and wrappers", () => {
@@ -33,13 +33,13 @@ describe("tool icons on the command fragment (docs/SIDEBAR.md)", () => {
     expect(splitCommand("FOO=1 BAR=2 claude").tool).toBe("claude");
     expect(splitCommand("npx opencode").tool).toBe("opencode");
     expect(splitCommand("pnpm dlx opencode run").tool).toBe("opencode");
-    expect(splitCommand("pnpm dlx opencode run").rest).toBe("run");
+    expect(splitCommand("pnpm dlx opencode run").program).toBe("opencode");
   });
 
-  it("leaves an unrecognised program as text, mark-less", () => {
+  it("leaves an unrecognised program as its bare name, mark-less", () => {
     expect(splitCommand("hx src/main.rs")).toEqual({
       tool: null,
-      rest: "hx src/main.rs",
+      program: "hx",
     });
     // A wrapper with nothing after it is not a tool either.
     expect(splitCommand("sudo").tool).toBeNull();

web/src/toolIcon.ts

@@ -2,11 +2,11 @@
  *
  * A session's command line starts with the program that runs it, and that
  * program is nearly always one of a handful of agents or a shell. Rendering it
- * as its own mark buys back most of the fragment's width, which the sidebar
+ * as its own mark buys back the whole fragment's width — the arguments are
- * spends on the rest of the command line instead.
+ * dropped, so a card says which tool runs, not how it was invoked.
  *
- * Recognition is deliberately narrow: an unrecognised program keeps its text,
+ * Recognition is deliberately narrow: an unrecognised program keeps its name
- * so the fragment never renders a mark that stands for the wrong tool.
+ * as text, so the fragment never renders a mark that stands for the wrong tool.
  */
 
 /** Command wrappers that run another program: the tool is what follows. */
@@ -48,15 +48,15 @@ export const TOOL_LABELS: Record<string, string> = {
 export interface CommandParts {
   /** Icon id, or `null` when the program is not one we have a mark for. */
   tool: string | null;
-  /** What is left of the command line once the icon stands for the program.
+  /** The program the command runs, basenamed and stripped of its arguments —
-   * Empty when the icon says everything the command line said. */
+   * what a card shows when there is no icon to show instead. */
-  rest: string;
+  program: string;
 }
 
-/** Split a command line into the tool its icon stands for and the remainder.
+/** Split a command line into the tool its icon stands for and the program name.
  *
- * `claude --resume` → `{tool: "claude", rest: "--resume"}`; an unrecognised
+ * `claude --resume` → `{tool: "claude", program: "claude"}`; an unrecognised
- * `hx src/` keeps the whole line as `rest` with no tool. */
+ * `hx src/` keeps `hx` as the program with no tool. */
 export function splitCommand(command: string): CommandParts {
   const words = command.trim().split(/\s+/).filter(Boolean);
   let i = 0;
@@ -68,23 +68,22 @@ export function splitCommand(command: string): CommandParts {
       i += 1;
       continue;
     }
-    const program = basename(word);
+    const wrapper = basename(word).toLowerCase();
-    if (WRAPPERS.has(program)) {
+    if (WRAPPERS.has(wrapper)) {
       i += 1;
-      if ((program === "pnpm" || program === "yarn") && words[i] === "dlx") i += 1;
+      if ((wrapper === "pnpm" || wrapper === "yarn") && words[i] === "dlx") i += 1;
       continue;
     }
     break;
   }
-  if (i >= words.length) return { tool: null, rest: command.trim() };
+  if (i >= words.length) return { tool: null, program: command.trim() };
-  const tool = BY_PROGRAM[basename(words[i])] ?? null;
+  const program = basename(words[i]);
-  if (!tool) return { tool: null, rest: command.trim() };
+  return { tool: BY_PROGRAM[program.toLowerCase()] ?? null, program };
-  return { tool, rest: words.slice(i + 1).join(" ") };
 }
 
 function basename(word: string): string {
   const cut = word.lastIndexOf("/");
-  return (cut >= 0 ? word.slice(cut + 1) : word).toLowerCase();
+  return cut >= 0 ? word.slice(cut + 1) : word;
 }
 
 /** Anthropic's burst: tapered rays around a centre, long ones on the axes. */

web/src/types.ts

@@ -253,7 +253,12 @@ export type ClientControl =
   | { type: "Error"; code: string; message: string };
 
 export interface ApiError {
-  error: { code: string; message: string };
+  error: {
+    code: string;
+    message: string;
+    /** Set only by the kill guard (#79): what blocked the unforced kill. */
+    unsaved_work?: InTheWay;
+  };
 }
 
 export function sessionName(s: Session): string {