feat(vision): prefix consultation tab titles with 'IMAGE - '

When a non-vision model (e.g. GLM) calls consult_vision, the new Kimi
consultation tab now shows 'IMAGE - <question>' instead of the bare
question-derived title, making image-consultation tabs visually
distinguishable from normal conversation tabs.

- Add formatConsultationTitle(question) pure helper (pure.ts): prefixes
  'IMAGE - ' and truncates the question to 80 chars (matching the
  conversation store's TITLE_MAX) with an ellipsis.
- Add setConversationTitle dep to VisionHandoffDeps, wired in the
  extension to the conversation store's setConversationTitle.
- Call it in consultVision BEFORE the turn starts so the title is
  correct from the first moment (the store keeps a non-'Untitled'
  title on first message append). Best-effort: a title-write failure
  logs a warning but does not break the consultation.
- Tests: 4 pure + 2 service (title set + optional-dep graceful).

5 files changed, 124 insertions, 0 deletions

diff --git a/packages/vision-handoff/src/extension.ts b/packages/vision-handoff/src/extension.ts
index faf4621..08fddca 100644
--- a/packages/vision-handoff/src/extension.ts
+++ b/packages/vision-handoff/src/extension.ts
@@ -183,6 +183,10 @@ export async function activate(host: HostAPI): Promise<void> {
       const store = host.getService(conversationStoreHandle);
       await store.setImageTranscription(conversationId, url, text);
     },
+    setConversationTitle: async (conversationId: string, title: string) => {
+      const store = host.getService(conversationStoreHandle);
+      await store.setConversationTitle(conversationId, title);
+    },
     logger: host.logger.child({ extensionId: "vision-handoff" }),
   });
 
diff --git a/packages/vision-handoff/src/pure.test.ts b/packages/vision-handoff/src/pure.test.ts
index e3fcf58..21b1224 100644
--- a/packages/vision-handoff/src/pure.test.ts
+++ b/packages/vision-handoff/src/pure.test.ts
@@ -3,6 +3,7 @@ import { describe, expect, it } from "vitest";
 import {
   collectTextFromStream,
   findVisionModelName,
+  formatConsultationTitle,
   formatConsultResult,
   formatImagePlaceholder,
   formatNoVisionPlaceholder,
@@ -155,3 +156,25 @@ describe("formatConsultResult", () => {
     expect(result).not.toContain("spaced  ");
   });
 });
+
+describe("formatConsultationTitle", () => {
+  it("prefixes the question with 'IMAGE - '", () => {
+    expect(formatConsultationTitle("What error is shown?")).toBe("IMAGE - What error is shown?");
+  });
+
+  it("truncates long questions to 80 chars with an ellipsis (matching the store's TITLE_MAX)", () => {
+    const long = "x".repeat(100);
+    const title = formatConsultationTitle(long);
+    expect(title).toBe(`IMAGE - ${"x".repeat(80)}…`);
+    expect(title.length).toBe("IMAGE - ".length + 80 + 1); // prefix + 80 + ellipsis
+  });
+
+  it("does not truncate questions at or under 80 chars", () => {
+    expect(formatConsultationTitle("x".repeat(80))).toBe(`IMAGE - ${"x".repeat(80)}`);
+    expect(formatConsultationTitle("x".repeat(79))).toBe(`IMAGE - ${"x".repeat(79)}`);
+  });
+
+  it("handles an empty question", () => {
+    expect(formatConsultationTitle("")).toBe("IMAGE - ");
+  });
+});
diff --git a/packages/vision-handoff/src/pure.ts b/packages/vision-handoff/src/pure.ts
index 5eeb1a3..af3476f 100644
--- a/packages/vision-handoff/src/pure.ts
+++ b/packages/vision-handoff/src/pure.ts
@@ -109,6 +109,32 @@ export function formatNoVisionPlaceholder(): string {
 }
 
 /**
+ * Maximum length of the consultation title body (matching the conversation
+ * store's `TITLE_MAX`). The question is truncated to this before the
+ * `"IMAGE - "` prefix is applied so the consultation tab's title stays in line
+ * with the store's own title-derivation limit.
+ */
+const CONSULTATION_TITLE_MAX = 80;
+
+/**
+ * Format the title for a vision consultation conversation tab. The title is
+ * `"IMAGE - "` prefixed to the (truncated) question so the tab is visually
+ * distinguishable from normal conversation tabs. The question is truncated to
+ * match the conversation store's title-derivation limit (`TITLE_MAX = 80`).
+ *
+ * Pure.
+ *
+ * @param question  The question the model asked the vision model.
+ */
+export function formatConsultationTitle(question: string): string {
+  const body =
+    question.length > CONSULTATION_TITLE_MAX
+      ? `${question.slice(0, CONSULTATION_TITLE_MAX)}…`
+      : question;
+  return `IMAGE - ${body}`;
+}
+
+/**
  * Format the `consult_vision` tool's result string. Returns the conversation ID
  * (so the model / user can continue the vision consultation), the vision model's
  * response, and a note that follow-up questions use the dispatch CLI (the model
diff --git a/packages/vision-handoff/src/service.test.ts b/packages/vision-handoff/src/service.test.ts
index 4667dbc..8c4117e 100644
--- a/packages/vision-handoff/src/service.test.ts
+++ b/packages/vision-handoff/src/service.test.ts
@@ -59,6 +59,7 @@ function makeDeps(overrides: Partial<VisionHandoffDeps> = {}): VisionHandoffDeps
         : undefined,
     ),
     readFileAsDataUrl: vi.fn(async (path: string) => `data:image/png;base64,FILE(${path})`),
+    setConversationTitle: vi.fn(async (_conversationId: string, _title: string) => {}),
     ...overrides,
   };
 }
@@ -257,6 +258,51 @@ describe("VisionHandoffService.consultVision", () => {
     expect(call.images?.[0]?.url).toBe("data:image/png;base64,img1");
   });
 
+  it("labels the consultation tab with an 'IMAGE - ' prefixed title", async () => {
+    const deps = makeDeps();
+    const { orchestrator } = makeOrchestratorDouble("The error is on line 12.");
+    deps.resolveOrchestrator = () => orchestrator;
+    const svc = createVisionHandoffService(deps);
+
+    // Register an image first (as prepareForProvider would).
+    const messages: ChatMessage[] = [
+      { role: "user", chunks: [{ type: "image", url: "data:image/png;base64,img1" }] },
+    ];
+    await svc.prepareForProvider(messages, "umans/umans-glm-5.2", { conversationId: "conv-1" });
+
+    const result = await svc.consultVision("What error is shown?", {
+      conversationId: "conv-1",
+      imageIds: [1],
+    });
+
+    expect("error" in result).toBe(false);
+    // The title was set with the IMAGE - prefix + the question.
+    expect(deps.setConversationTitle).toHaveBeenCalledOnce();
+    const [titleConvId, title] = (deps.setConversationTitle as ReturnType<typeof vi.fn>).mock
+      .calls[0];
+    expect(titleConvId).toBe((result as { conversationId: string }).conversationId);
+    expect(title).toBe("IMAGE - What error is shown?");
+  });
+
+  it("does not call setConversationTitle when it is not provided", async () => {
+    const deps = makeDeps({ setConversationTitle: undefined });
+    const { orchestrator } = makeOrchestratorDouble("response");
+    deps.resolveOrchestrator = () => orchestrator;
+    const svc = createVisionHandoffService(deps);
+
+    const messages: ChatMessage[] = [
+      { role: "user", chunks: [{ type: "image", url: "data:image/png;base64,img1" }] },
+    ];
+    await svc.prepareForProvider(messages, "umans/umans-glm-5.2", { conversationId: "conv-1" });
+
+    // Should NOT throw — setConversationTitle is optional.
+    const result = await svc.consultVision("What?", {
+      conversationId: "conv-1",
+      imageIds: [1],
+    });
+    expect("error" in result).toBe(false);
+  });
+
   it("opens a consultation with a file path image", async () => {
     const deps = makeDeps();
     const { orchestrator } = makeOrchestratorDouble("It's a diagram.");
diff --git a/packages/vision-handoff/src/service.ts b/packages/vision-handoff/src/service.ts
index cc13d93..01245df 100644
--- a/packages/vision-handoff/src/service.ts
+++ b/packages/vision-handoff/src/service.ts
@@ -34,6 +34,7 @@ import { defineService, type ServiceHandle } from "@dispatch/kernel";
 import {
   collectTextFromStream,
   findVisionModelName,
+  formatConsultationTitle,
   formatConsultResult,
   formatImagePlaceholder,
   formatNoVisionPlaceholder,
@@ -146,6 +147,14 @@ export interface VisionHandoffDeps {
    * Best-effort.
    */
   readonly deleteConversationImages?: (conversationId: string) => Promise<void>;
+  /**
+   * Set the human-readable title of a conversation. Used to label vision
+   * consultation tabs with an `"IMAGE - "` prefix so they're visually
+   * distinguishable from normal conversation tabs. Backed by the conversation
+   * store's `setConversationTitle`. Optional — when absent, consultation tabs
+   * keep their default (question-derived) title.
+   */
+  readonly setConversationTitle?: (conversationId: string, title: string) => Promise<void>;
   /** Generate a new conversation ID for a consultation. Defaults to crypto.randomUUID. */
   readonly generateId?: () => string;
   readonly logger?: Logger;
@@ -622,6 +631,22 @@ export function createVisionHandoffService(deps: VisionHandoffDeps): VisionHando
         fromConversation: opts.conversationId,
       });
 
+      // Label the consultation tab with an "IMAGE - " prefix so it's visually
+      // distinguishable from normal conversation tabs. Set BEFORE the turn
+      // starts so the tab shows the correct title from the first moment (the
+      // store keeps a non-"Untitled" title on first message append).
+      if (deps.setConversationTitle !== undefined) {
+        try {
+          await deps.setConversationTitle(consultationId, formatConsultationTitle(question));
+        } catch (err) {
+          // Best-effort — don't let a title-write failure break the consultation.
+          log?.warn("vision-handoff: failed to set consultation title", {
+            consultationId,
+            error: err instanceof Error ? err.message : String(err),
+          });
+        }
+      }
+
       let responseText = "";
       let errorMessage = "";
       try {