fix(ui): stream phase progress without gates

frontend/src/api/types.ts

@@ -98,7 +98,7 @@ export type StreamEvent =
     }
   | { type: "usage"; usage: TokenUsage }
   | { type: "info"; level?: "info" | "warning" | "error"; text: string }
-  | { type: "system_event"; event: string };
+  | { type: "system_event"; event: string; phase?: string };
 
 export interface SessionSummary {
   id: string;

frontend/src/shell/WorkflowBar.test.tsx

@@ -29,6 +29,18 @@ test("dots carry done / running / pending states around the active phase", () =>
   expect(screen.getByTestId("phase-F5")).toHaveAttribute("data-state", "pending");
 });
 
+test("phase_started colors a phase even when no human gate was rendered", () => {
+  const store = useSessionStore.getState();
+  store.setPhase("F1");
+  store.applyEvent({ type: "system_event", event: "phase_started", phase: "F2" });
+
+  render(<WorkflowBar />);
+
+  expect(screen.getByTestId("phase-F1")).toHaveAttribute("data-state", "done");
+  expect(screen.getByTestId("phase-F2")).toHaveAttribute("data-state", "running");
+  expect(screen.getByTestId("phase-F3")).toHaveAttribute("data-state", "pending");
+});
+
 test("the active dot turns to the error state when phaseError flags it", () => {
   const st = useSessionStore.getState();
   st.applyEvent({ type: "ui_request", ui_request: { id: "u", widget: "select", phase: "F3_x" } });

frontend/src/store/sessionStore.test.ts

@@ -184,6 +184,19 @@ test("ui_request without a phase keeps the existing currentPhase", () => {
   expect(useSessionStore.getState().currentPhase).toBe("F2");
 });
 
+test("phase_started advances progress even when the phase has no human gate", () => {
+  const store = useSessionStore.getState();
+  store.setPhase("F1");
+
+  store.applyEvent({
+    type: "system_event",
+    event: "phase_started",
+    phase: "F2_memory",
+  });
+
+  expect(useSessionStore.getState().currentPhase).toBe("F2");
+});
+
 test("agentActive lifecycle: off by default, on with activity, off on agent_end", () => {
   const st = useSessionStore.getState();
   expect(useSessionStore.getState().agentActive).toBe(false);

frontend/src/store/sessionStore.ts

@@ -176,14 +176,26 @@ export const useSessionStore = create<SessionState>((set) => ({
           : { stepMessages, activityLog };
       }
       if (e.type === "system_event") {
+        const currentPhase = e.event === "phase_started"
+          ? phaseOf(e.phase, st.currentPhase)
+          : st.currentPhase;
         const activityLog = [
           ...st.activityLog,
           {
             kind: "lifecycle" as const,
-            phase: st.currentPhase,
+            phase: currentPhase,
             text: lifecycleText(e.event),
           },
         ];
+        if (e.event === "phase_started") {
+          return {
+            lastSystemEvent: e,
+            activityLog,
+            currentPhase,
+            phaseError: null,
+            agentActive: true,
+          };
+        }
         return e.event === "agent_end"
           ? { lastSystemEvent: e, activityLog, agentActive: false }
           : { lastSystemEvent: e, activityLog };