fix: restore model activity reasoning stream

backend/src/bridge/session-bridge.ts

@@ -3,6 +3,7 @@ import type { RpcClient } from "../rpc/rpc-client.js";
 export type ClientEvent =
   | { type: "ui_request"; ui_request: any }
   | { type: "text_delta"; text: string }
+  | { type: "activity_delta"; text: string }
   | { type: "info"; [k: string]: any }
   | { type: "system_event"; [k: string]: any };
 
@@ -27,6 +28,8 @@ export class SessionBridge {
         this.fan({ type: "info", level: m.notifyType ?? "info", text: m.message ?? "" });
       } else if (m.type === "message_update" && m.assistantMessageEvent?.type === "text_delta") {
         this.fan({ type: "text_delta", text: m.assistantMessageEvent.delta ?? "" });
+      } else if (m.type === "message_update" && m.assistantMessageEvent?.type === "thinking_delta") {
+        this.fan({ type: "activity_delta", text: m.assistantMessageEvent.delta ?? "" });
       } else if (m.type === "text_delta") {
         this.fan({ type: "text_delta", text: m.text ?? "" });
       // tool_execution_* events are intentionally NOT forwarded: they clutter

backend/src/routes/sessions.ts

@@ -69,8 +69,7 @@ export function sessionRoutes(
     const options = {
       provider: s.provider,
       model: s.model,
-      // Keep the saved preference in the manifest; F1 starts tool-first.
-      thinking: "off",
+      thinking: s.thinking,
       author: getUser(req).id,
       question: b.question,
     };
@@ -117,9 +116,7 @@ export function sessionRoutes(
     const options = {
       provider: saved?.provider,
       model: saved?.model,
-      // Phase 1 must reach a widget instead of exposing a long reasoning trace.
-      // The session keeps its saved preference for later turns.
-      thinking: "off",
+      thinking: saved?.thinking ?? settings.thinking,
       author: getUser(req).id,
       mode: "resume" as const,
     };

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);