fix(backend): track Pi turn lifecycle

backend/test/session-bridge.test.ts

@@ -42,6 +42,78 @@ test("real Pi thinking_delta becomes a dedicated activity_delta to the FE", () =
   expect(seen).toEqual([{ type: "activity_delta", text: "Valuto le ambiguità" }]);
 });
 
+test("assistant provider errors are sanitized and leave the turn failed", () => {
+  const { rpc, fire } = fakeRpc();
+  const bridge = new SessionBridge(rpc);
+  const seen: any[] = [];
+  bridge.onClientEvent((event) => seen.push(event));
+  bridge.beginTurn();
+
+  fire({
+    type: "message_end",
+    message: {
+      role: "assistant",
+      stopReason: "error",
+      errorMessage: "Connection failed for https://secret.invalid/?api_key=DO_NOT_LEAK",
+    },
+  });
+  fire({ type: "agent_end", messages: [] });
+
+  expect(bridge.turnState()).toBe("failed");
+  expect(seen).toContainEqual({
+    type: "info",
+    level: "error",
+    text: "Model request failed. Check provider connectivity, then Resume the session.",
+  });
+  expect(JSON.stringify(seen)).not.toContain("DO_NOT_LEAK");
+});
+
+test("reviewer wait and response transition waiting back to running", () => {
+  const { rpc, fire } = fakeRpc();
+  const bridge = new SessionBridge(rpc);
+  bridge.beginTurn();
+  fire({
+    type: "extension_ui_request",
+    id: "pi-1",
+    method: "input",
+    title: JSON.stringify({ id: "gate-1", widget: "select" }),
+  });
+  expect(bridge.turnState()).toBe("waiting");
+  bridge.respond({ id: "gate-1", choices: ["approve"] });
+  expect(bridge.turnState()).toBe("running");
+  fire({ type: "agent_end", messages: [] });
+  expect(bridge.turnState()).toBe("idle");
+});
+
+test("agent_start transitions an idle turn to running", () => {
+  const { rpc, fire } = fakeRpc();
+  const bridge = new SessionBridge(rpc);
+  const seen: any[] = [];
+  bridge.onClientEvent((event) => seen.push(event));
+
+  expect(bridge.turnState()).toBe("idle");
+  fire({ type: "agent_start" });
+
+  expect(bridge.turnState()).toBe("running");
+  expect(seen).toContainEqual({ type: "system_event", event: "agent_start" });
+});
+
+test("agent_end leaves a pending reviewer wait intact", () => {
+  const { rpc, fire } = fakeRpc();
+  const bridge = new SessionBridge(rpc);
+  bridge.beginTurn();
+  fire({
+    type: "extension_ui_request",
+    id: "pi-1",
+    method: "input",
+    title: JSON.stringify({ id: "gate-1", widget: "select" }),
+  });
+
+  fire({ type: "agent_end", messages: [] });
+
+  expect(bridge.turnState()).toBe("waiting");
+});
+
 test("extension_ui_request nativo (method:input, title=json) diventa ui_request col descriptor ed è il pendente", () => {
   const { rpc, fire } = fakeRpc();
   const b = new SessionBridge(rpc);
@@ -79,8 +151,20 @@ test("agent_end di Pi diventa un system_event agent_end per il FE", () => {
   expect(seen).toEqual([{ type: "system_event", event: "agent_end" }]);
 });
 
-test("steer invia un comando steer", () => {
-  const { rpc, sent } = fakeRpc();
-  new SessionBridge(rpc).steer("considera solo il 2024");
+test("steer invia un comando steer e riattiva il turno", () => {
+  const { rpc, sent, fire } = fakeRpc();
+  const bridge = new SessionBridge(rpc);
+  bridge.beginTurn();
+  fire({
+    type: "extension_ui_request",
+    id: "pi-1",
+    method: "input",
+    title: JSON.stringify({ id: "gate-1", widget: "select" }),
+  });
+  expect(bridge.turnState()).toBe("waiting");
+
+  bridge.steer("considera solo il 2024");
+
   expect(sent.at(-1)).toEqual({ type: "steer", message: "considera solo il 2024" });
+  expect(bridge.turnState()).toBe("running");
 });