fix: restore model activity reasoning stream

backend/test/routes-sessions.test.ts

@@ -47,6 +47,65 @@ test("POST /sessions usa i settings (workspace/provider/model/thinking) e crea+a
   unlinkSync(modelKey);
 });
 
+test("POST /sessions configura Pi con il thinking globale selezionato", async () => {
+  let configured: any;
+  const bridge = { onClientEvent: () => {}, emitClientEvent: () => {} };
+  const runtime = { bridge } as any;
+  const mgr = {
+    createFor: () => runtime,
+    configure: async (_rt: any, options: any) => { configured = options; },
+    start: () => {},
+    teardown: () => {},
+  } as any;
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    mgr,
+    thtRunner: {
+      ollamaEnsure: async () => ({ ok: true }),
+      searchPack: async () => {},
+      sessionNew: async () => ({ id: "s-thinking" }),
+    } as any,
+    getSettings: () => ({ workspace: "psd", provider: "zai", model: "glm-5.2", thinking: "high" }) as any,
+  });
+
+  await app.inject({ method: "POST", url: "/sessions", payload: { question: "q" } });
+  await new Promise((resolve) => setImmediate(resolve));
+
+  expect(configured.thinking).toBe("high");
+});
+
+test("POST /sessions/:id/resume configura Pi con il thinking persistito", async () => {
+  let configured: any;
+  const bridge = { onClientEvent: () => {}, emitClientEvent: () => {} };
+  const runtime = { bridge } as any;
+  const mgr = {
+    get: () => undefined,
+    createFor: () => runtime,
+    configure: async (_rt: any, options: any) => { configured = options; },
+    start: () => {},
+    teardown: () => {},
+  } as any;
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    mgr,
+    thtRunner: {
+      ollamaEnsure: async () => ({ ok: true }),
+      sessionShow: async () => ({
+        status: "open",
+        archived: false,
+        provider: "zai",
+        model: "glm-5.2",
+        thinking: "medium",
+      }),
+      reopenSession: async () => {},
+    } as any,
+    getSettings: () => ({ workspace: "psd", thinking: "low" }) as any,
+  });
+
+  await app.inject({ method: "POST", url: "/sessions/s-thinking/resume" });
+  await new Promise((resolve) => setImmediate(resolve));
+
+  expect(configured.thinking).toBe("medium");
+});
+
 test("POST /sessions/:id/response inoltra al bridge (no error)", async () => {
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {

backend/test/session-bridge.test.ts

@@ -28,6 +28,20 @@ test("real Pi message_update (assistantMessageEvent text_delta) becomes a text_d
   expect(seen).toHaveLength(1);
 });
 
+test("real Pi thinking_delta becomes a dedicated activity_delta to the FE", () => {
+  const { rpc, fire } = fakeRpc();
+  const b = new SessionBridge(rpc);
+  const seen: any[] = [];
+  b.onClientEvent((e) => seen.push(e));
+
+  fire({
+    type: "message_update",
+    assistantMessageEvent: { type: "thinking_delta", contentIndex: 0, delta: "Valuto le ambiguità" },
+  });
+
+  expect(seen).toEqual([{ type: "activity_delta", text: "Valuto le ambiguità" }]);
+});
+
 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);