feat(maestro): show image previews in user message bubbles

Uploaded images now render as thumbnails in the user bubble instead of
showing only the server file path as text.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/STRUCTURED-VIEW.md

@@ -193,10 +193,13 @@ choices, not daemon ones.
   one collapsed turn activity block. `AgentText` and `AgentThought` rows that
   appear *between* tool rows in the same turn are absorbed into the group
   (intermediate narration); the last `AgentText` with no subsequent tool stays
-  outside as the prominent final answer. The header still reads
-  "N tool calls" (counting only tool rows). Opening the group reveals tools
-  and intermediate text in chronological order, with the text rendered in a
-  subdued style.
+  outside as the prominent final answer. While a turn is still active
+  (responding or thinking), the most recent intermediate `AgentText` or
+  `AgentThought` in the group is kept outside as visible narration — replaced
+  by the next text row when one arrives, and absorbed into the group when the
+  turn ends. The header still reads "N tool calls" (counting only tool rows).
+  Opening the group reveals tools and intermediate text in chronological
+  order, with the text rendered in a subdued style.
 - The web client's user, agent, thought, tool-detail, and notice text blocks
   copy their complete source text when clicked or keyboard-activated.
 - The web client consumes `available_commands_update` notices as the live

web/src/structured.test.ts

@@ -446,6 +446,40 @@ describe("structured connection: data flow", () => {
     conn.dispose();
   });
 
+  it("keeps last intermediate text outside group while turn is active", () => {
+    const ws = new FakeSocket();
+    const conn = mount({ sockets: [ws] });
+    ws.open();
+    const respondingState: ReducedState = {
+      turn: { responding: true, thinking: false, active_tool_calls: [] },
+    };
+    ws.emit({
+      type: "transcript_snapshot",
+      snapshot: {
+        cursor: 6,
+        rows: [
+          row("user:1", "user", { content: { type: "text", text: "do it" } }),
+          toolRow("tool:1", "one"),
+          row("agent:1", "agent_text", { content: { type: "text", text: "Now fixing" } }),
+          toolRow("tool:2", "two"),
+          row("agent:2", "agent_text", { content: { type: "text", text: "Found more" } }),
+          toolRow("tool:3", "three"),
+        ],
+      },
+    });
+    ws.emit({ type: "reduced_state", state: respondingState });
+    // While the turn is active, the last intermediate text (agent:2) stays
+    // outside the collapsed group so it's visible as current narration.
+    expect(conn.el.querySelector('[data-row-id="agent:2"]')?.closest(".st-tool-group")).toBeNull();
+    // Earlier intermediate text (agent:1) is still inside the group.
+    expect(conn.el.querySelector('[data-row-id="agent:1"]')?.closest(".st-tool-group")).not.toBeNull();
+    // When the turn ends, all intermediate text is absorbed.
+    ws.emit({ type: "reduced_state", state: idleState });
+    expect(conn.el.querySelector('[data-row-id="agent:2"]')?.closest(".st-tool-group")).not.toBeNull();
+    expect(conn.el.querySelector('[data-row-id="agent:1"]')?.closest(".st-tool-group")).not.toBeNull();
+    conn.dispose();
+  });
+
   it("keeps an expanded running tool open without emitting a click when patched", () => {
     const ws = new FakeSocket();
     const conn = mount({ sockets: [ws] });

web/src/structured.ts

@@ -85,10 +85,10 @@ export function createStructuredConnection(
       <div class="structured-main">
         <div class="structured-scroll">
           <div class="structured-rows"></div>
-        </div>
-        <div class="structured-activity" role="status" aria-live="polite" hidden>
-          <span class="structured-activity-pulse" aria-hidden="true"></span>
-          <span class="structured-activity-text">Thinking</span>
+          <div class="structured-activity" role="status" aria-live="polite" hidden>
+            <span class="structured-activity-pulse" aria-hidden="true"></span>
+            <span class="structured-activity-text">Thinking</span>
+          </div>
         </div>
         <form class="structured-composer">
           <button type="button" class="btn btn-ghost btn-icon structured-attach" aria-label="Attach files" title="Attach files (up to 20 MiB each)">
@@ -253,6 +253,8 @@ export function createStructuredConnection(
   let activityTimer: number | null = null;
   const promptQueue: QueuedPrompt[] = [];
   let promptRequestPending = false;
+  /** Server path → object URL for uploaded images, so user bubbles can show previews. */
+  const imageObjectUrls = new Map<string, string>();
 
   // Within 64px, wheel and touch imprecision should still count as following.
   const FOLLOW_BOTTOM_THRESHOLD_PX = 64;
@@ -383,6 +385,9 @@ export function createStructuredConnection(
     }
   }
 
+  /** Pattern matching `Attached file "name": "path"` references appended by dispatchPrompt. */
+  const attachedFileRe = /Attached file "(?:[^"\\]|\\.)*": "((?:[^"\\]|\\.)*)"/g;
+
   function buildRowElement(row: TranscriptRow): HTMLElement | null {
     const el = buildTranscriptRow(
       row,
@@ -399,6 +404,39 @@ export function createStructuredConnection(
     if (el.querySelector(".st-tool-head")?.getAttribute("aria-expanded") !== "true") {
       expandedRowIds.delete(row.id);
     }
+    // Inject image previews into user message bubbles and strip the path text.
+    if (row.kind === "user" && imageObjectUrls.size > 0) {
+      const data = row.data as { content?: { type: string; text?: string } } | undefined;
+      const text = data?.content?.type === "text" ? data.content.text ?? "" : "";
+      const body = el.querySelector(".st-body");
+      if (body && text) {
+        const images: string[] = [];
+        attachedFileRe.lastIndex = 0;
+        let match: RegExpExecArray | null;
+        while ((match = attachedFileRe.exec(text)) !== null) {
+          const serverPath = JSON.parse(`"${match[1]}"`);
+          const objectUrl = imageObjectUrls.get(serverPath);
+          if (objectUrl) images.push(objectUrl);
+        }
+        if (images.length > 0) {
+          // Strip attachment reference lines from the displayed text.
+          const userText = body.querySelector(".st-user-text");
+          if (userText) {
+            const cleaned = text.replace(/\n\nAttached file "[^"]*": "[^"]*"/g, "").trim();
+            userText.textContent = cleaned;
+            if (!cleaned) userText.remove();
+          }
+          for (const src of images) {
+            const img = document.createElement("img");
+            img.className = "st-user-image";
+            img.src = src;
+            img.alt = "Uploaded image";
+            img.loading = "lazy";
+            body.appendChild(img);
+          }
+        }
+      }
+    }
     return el;
   }
 
@@ -453,6 +491,25 @@ export function createStructuredConnection(
       }
     }
     // pending at end of a turn = final text/approvals, stays outside (not flushed).
+
+    // While the turn is still active, keep the last intermediate text/thought
+    // row outside the collapsed group so it's visible as the agent's current
+    // narration. It gets absorbed on the next rebuild once newer content
+    // arrives or the turn ends.
+    const turnActive = state.turn.responding || state.turn.thinking;
+    if (turnActive) {
+      const lastGroup = groups.get(currentGid);
+      if (lastGroup) {
+        for (let i = lastGroup.rows.length - 1; i >= 0; i--) {
+          const kind = lastGroup.rows[i].kind;
+          if (kind === "agent_text" || kind === "agent_thought") {
+            lastGroup.rows.splice(i, 1);
+            break;
+          }
+        }
+      }
+    }
+
     return groups;
   }
 
@@ -698,6 +755,7 @@ export function createStructuredConnection(
 
   function renderActivity(): void {
     const active = state.turn.responding || state.turn.thinking || awaitingBeginGeneration !== null;
+    const wasHidden = activityEl.hidden;
     activityEl.hidden = !active;
     if (!active) {
       optimisticTurnStartedAt = null;
@@ -720,6 +778,11 @@ export function createStructuredConnection(
     }
     activityText.textContent = parts.join(" · ");
     if (activityTimer === null) activityTimer = window.setInterval(renderActivity, 1_000);
+    // Activity lives inside the scroll area; nudge scroll when it first appears.
+    if (wasHidden && followingBottom) {
+      beginTranscriptLayout(true);
+      finishTranscriptLayout();
+    }
   }
 
   function reconcileAwaitingBegin(): void {
@@ -735,15 +798,17 @@ export function createStructuredConnection(
   }
 
   function applyState(next: ReducedState, connectionGeneration: number): void {
+    const wasTurnActive = state.turn.responding || state.turn.thinking;
     state = next;
     stateSocketGeneration = connectionGeneration;
     reconcileAwaitingBegin();
+    const isTurnActive = state.turn.responding || state.turn.thinking;
     const newPendingId = state.pending_approval ? lastRowIdOfKind("approval") : null;
-    if (newPendingId !== pendingApprovalRowId) {
+    const needsRebuild = newPendingId !== pendingApprovalRowId || wasTurnActive !== isTurnActive;
+    if (needsRebuild) {
       updateTranscriptLayout(() => {
-        const prev = pendingApprovalRowId;
         pendingApprovalRowId = newPendingId;
-        if (prev !== null || newPendingId !== null) rebuildTranscript();
+        rebuildTranscript();
       });
     }
     renderConfig();
@@ -964,6 +1029,9 @@ export function createStructuredConnection(
       for (const attachment of submittedAttachments) {
         if (disposed) return;
         if (!attachment.path) attachment.path = (await uploadStructuredFile(sessionId, attachment.file)).path;
+        if (attachment.path && attachment.file.type.startsWith("image/")) {
+          imageObjectUrls.set(attachment.path, URL.createObjectURL(attachment.file));
+        }
       }
       if (disposed) return;
       const references = submittedAttachments.map(({ file, path }) =>
@@ -1203,6 +1271,8 @@ export function createStructuredConnection(
       closeCurrentSocket();
       expandedRowIds.clear();
       expandedGroupIds.clear();
+      for (const url of imageObjectUrls.values()) URL.revokeObjectURL(url);
+      imageObjectUrls.clear();
       scrollEl.removeEventListener("scroll", onTranscriptScroll);
       scrollEl.removeEventListener("click", onTranscriptClick, true);
       scrollEl.removeEventListener("wheel", stopSmoothFollow);

web/src/styles.css

@@ -2318,9 +2318,7 @@ input.leaf-rename:focus {
   gap: var(--sp-2);
   min-height: 30px;
   padding: var(--sp-1) var(--sp-3);
-  border-top: 1px solid var(--border);
   color: var(--muted);
-  background: var(--surface-2);
   font-size: var(--fs-11);
   font-variant-numeric: tabular-nums;
 }
@@ -2382,6 +2380,15 @@ input.leaf-rename:focus {
   overflow-wrap: anywhere;
 }
 
+.st-user-image {
+  display: block;
+  max-width: min(100%, 480px);
+  max-height: 360px;
+  margin-top: var(--sp-2);
+  border-radius: var(--r-1);
+  object-fit: contain;
+}
+
 /* agent prose: no card, no background — plain text is the point */
 .st-row-agent .st-body p {
   margin: 0 0 var(--sp-2);