agents: show draft cards only for drafts that exist on disk

src/app/AppShell.navigation.test.tsx

@@ -4350,38 +4350,56 @@ describe("AppShell global navigation", () => {
     ).not.toBeInTheDocument();
   });
 
-  it("returns to agent builder mode after going back then forward", async () => {
+  it("discards an untouched agent draft when navigating back, without prompting", async () => {
     const user = userEvent.setup();
+    // The placeholder really exists on disk: the backend lists it and it
+    // reads back unchanged.
+    const placeholder = {
+      type: "agent",
+      path: "/Users/test/.agents/agents/untitled-agent-created-session.md",
+      name: "Untitled agent created-sess",
+      description: "Draft",
+      content: "Draft in progress.",
+      global: true,
+      writable: true,
+      properties: { draft: true, builderSessionId: "created-session" },
+    };
+    mockListPersonaSources.mockResolvedValue([placeholder]);
+    mockReadAgentSourceFile.mockResolvedValue(placeholder);
+    // Once deleted, the file is no longer listed or readable.
+    mockDeletePersonaSource.mockImplementation(async () => {
+      mockListPersonaSources.mockResolvedValue([]);
+      mockReadAgentSourceFile.mockRejectedValue(new Error("not found"));
+    });
     renderAppShell();
 
     await user.click(screen.getByRole("button", { name: "Sidebar agents" }));
     await user.click(screen.getByRole("button", { name: "Create agent" }));
     await waitFor(() => {
       expect(screen.getByTestId("active-view")).toHaveTextContent("chat");
     });
-    await waitFor(() => {
-      expect(useChatSessionStore.getState().getActiveSession()).toMatchObject({
-        id: "created-session",
-        intent: "build-agent",
-      });
-    });
+    await waitForCreatedAgentBuilderTarget();
 
+    // Nothing was typed or edited, so leaving is silent: no "save this
+    // draft?" prompt, and the placeholder file and its builder state are
+    // gone rather than lingering as an untitled draft.
     await user.click(screen.getByRole("button", { name: "Back" }));
     await waitFor(() => {
       expect(screen.getByTestId("active-view")).toHaveTextContent("agents");
     });
-
-    await user.click(screen.getByRole("button", { name: "Forward" }));
+    expect(
+      screen.queryByText("Save this agent draft?"),
+    ).not.toBeInTheDocument();
     await waitFor(() => {
-      expect(screen.getByTestId("active-view")).toHaveTextContent("chat");
+      expect(mockDeletePersonaSource).toHaveBeenCalledWith(
+        "/Users/test/.agents/agents/untitled-agent-created-session.md",
+      );
     });
     await waitFor(() => {
-      expect(useChatSessionStore.getState().getActiveSession()).toMatchObject({
-        id: "created-session",
-        intent: "build-agent",
-        targetAgentPath:
-          "/Users/test/.agents/agents/untitled-agent-created-session.md",
-      });
+      const session = useChatSessionStore
+        .getState()
+        .getSession("created-session");
+      expect(session?.intent ?? null).toBeNull();
     });
   });
 

src/features/agents/capabilities/AgentBuilderCapability.tsx

@@ -17,7 +17,7 @@ import type { ChatSession } from "@/features/chat/stores/chatSessionStore";
 import { useChatSessionStore } from "@/features/chat/stores/chatSessionStore";
 import {
   agentSourceToPersona,
-  listPersonas,
+  listAgentGallery,
   type AgentSourceEntry,
 } from "@/shared/api/agents";
 
@@ -51,37 +51,48 @@ export function AgentBuilderCapability({
   const { t } = useTranslation("agents");
   const patchSession = useChatSessionStore((state) => state.patchSession);
 
-  const refreshPersonas = useCallback(async () => {
-    const personas = await listPersonas();
-    useAgentStore.getState().setPersonas(personas);
-  }, []);
-
   const completeBuilder = useCallback(
     (source: AgentSourceEntry, refreshErrorMessage: string) => {
       clearBuilderSessionState(session.id);
 
       // Promotion is the durable source of truth. Seed the store immediately
       // so the destination profile exists even if the follow-up disk refresh
-      // fails or has not observed the promoted source yet.
+      // fails or has not observed the promoted source yet. Running the writes
+      // as a gallery mutation fences out any disk refresh that started before
+      // the promotion and would otherwise repaint the draft card.
       const promotedPersona = agentSourceToPersona(source);
       const agentStore = useAgentStore.getState();
-      const existingPersona = agentStore.personas.find(
-        (persona) => persona.id === promotedPersona.id,
-      );
-      if (existingPersona) {
-        agentStore.updatePersona(promotedPersona.id, promotedPersona);
-      } else {
-        agentStore.addPersona(promotedPersona);
-      }
+      const seeded = agentStore.mutateGallery(() => {
+        const current = useAgentStore.getState();
+        const existingPersona = current.personas.find(
+          (persona) => persona.id === promotedPersona.id,
+        );
+        if (existingPersona) {
+          current.updatePersona(promotedPersona.id, promotedPersona);
+        } else {
+          current.addPersona(promotedPersona);
+        }
+        // The draft just became this agent; drop its card without waiting
+        // for the disk refresh so the gallery never shows both at once.
+        for (const draft of current.draftSources) {
+          if (draft.properties?.builderSessionId === session.id) {
+            current.removeDraftSource(draft.path);
+          }
+        }
+      });
 
       onDraftPromoted?.(source);
       onAgentBuilderCompleted?.(promotedPersona.id);
 
-      void refreshPersonas().catch((error) => {
-        console.error(refreshErrorMessage, error);
-      });
+      // The refresh must start after the mutation releases the fence, or the
+      // fence would (correctly) reject it as having begun mid-mutation.
+      void seeded
+        .then(() => agentStore.refreshGallery(listAgentGallery))
+        .catch((error) => {
+          console.error(refreshErrorMessage, error);
+        });
     },
-    [onAgentBuilderCompleted, onDraftPromoted, refreshPersonas, session.id],
+    [onAgentBuilderCompleted, onDraftPromoted, session.id],
   );
 
   const handleDraftPromoted = useCallback(

src/features/agents/capabilities/__tests__/AgentBuilderCapability.test.tsx

@@ -1,4 +1,4 @@
-import { act, fireEvent, screen } from "@testing-library/react";
+import { act, fireEvent, screen, waitFor } from "@testing-library/react";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { renderWithProviders } from "@/test/render";
 
@@ -15,7 +15,7 @@ const apiMocks = vi.hoisted(() => ({
   listPersonaSources: vi.fn(),
   readAgentSourceFile: vi.fn(),
   updatePersonaSource: vi.fn(),
-  listPersonas: vi.fn(),
+  listAgentGallery: vi.fn(),
   hasRealAgentDescription: (description: string | null | undefined) => {
     const normalized = description?.trim().toLowerCase();
     return Boolean(
@@ -24,7 +24,13 @@ const apiMocks = vi.hoisted(() => ({
   },
 }));
 
-vi.mock("@/shared/api/agents", () => apiMocks);
+vi.mock("@/shared/api/agents", async (importOriginal) => ({
+  ...apiMocks,
+  // Pure mapper; the real one keeps the promotion path honest.
+  agentSourceToPersona: (
+    await importOriginal<typeof import("@/shared/api/agents")>()
+  ).agentSourceToPersona,
+}));
 
 vi.mock("@/features/agents/lib/agentTelemetry", () => telemetryMocks);
 
@@ -62,6 +68,7 @@ import {
   type ChatSession,
 } from "@/features/chat/stores/chatSessionStore";
 import type { AgentSourceEntry } from "@/shared/api/agents";
+import type { Persona } from "@/shared/types/agents";
 
 const existingAgentSource: AgentSourceEntry = {
   type: "agent",
@@ -103,7 +110,7 @@ describe("AgentBuilderCapability keep-save telemetry", () => {
     apiMocks.listPersonaSources.mockReset();
     apiMocks.readAgentSourceFile.mockReset();
     apiMocks.updatePersonaSource.mockReset();
-    apiMocks.listPersonas.mockReset();
+    apiMocks.listAgentGallery.mockReset();
     apiMocks.listPersonaSources.mockResolvedValue([existingAgentSource]);
     apiMocks.readAgentSourceFile.mockImplementation(
       async (_path: string, fallback?: AgentSourceEntry) =>
@@ -121,11 +128,14 @@ describe("AgentBuilderCapability keep-save telemetry", () => {
         },
       }),
     );
-    apiMocks.listPersonas.mockResolvedValue([]);
+    apiMocks.listAgentGallery.mockResolvedValue({ personas: [], drafts: [] });
     resetAgentBuilderSourceLifecycleForTests();
     useAgentStore.setState({
       personas: [],
       personasLoading: false,
+      draftSources: [],
+      galleryRevision: 0,
+      galleryMutationsInFlight: 0,
       providers: [],
     });
     useChatSessionStore.setState({
@@ -173,4 +183,40 @@ describe("AgentBuilderCapability keep-save telemetry", () => {
     expect(telemetryMocks.trackAgentEditCompleted).not.toHaveBeenCalled();
     expect(telemetryMocks.trackAgentCreateCompleted).not.toHaveBeenCalled();
   });
+
+  it("applies the disk refresh that follows a save, through the real gallery fence", async () => {
+    // The optimistic store seed runs as a gallery mutation; the follow-up
+    // listing must start after that mutation releases the fence, or the fence
+    // would reject it and the gallery would stay on the optimistic copy.
+    const fromDisk: Persona = {
+      id: existingAgentSource.path,
+      displayName: "Code Reviewer (as listed on disk)",
+      systemPrompt: existingAgentSource.content,
+      isBuiltin: false,
+      writable: true,
+      createdAt: "2026-06-09T00:00:00.000Z",
+      updatedAt: "2026-06-09T00:00:00.000Z",
+    };
+    apiMocks.listAgentGallery.mockResolvedValue({
+      personas: [fromDisk],
+      drafts: [],
+    });
+
+    renderWithProviders(
+      <AgentBuilderCapability
+        session={builderSession}
+        onAgentBuilderCompleted={vi.fn()}
+      />,
+    );
+    await screen.findByLabelText(/agent name/i);
+    fireEvent.click(screen.getByRole("button", { name: "Save changes" }));
+
+    await waitFor(() => {
+      expect(apiMocks.listAgentGallery).toHaveBeenCalledTimes(1);
+    });
+    await waitFor(() => {
+      expect(useAgentStore.getState().personas).toEqual([fromDisk]);
+    });
+    expect(useAgentStore.getState().galleryMutationsInFlight).toBe(0);
+  });
 });