feat: harden runtime readiness and session workflow

backend/test/routes-sessions.test.ts

@@ -28,6 +28,7 @@ test("POST /sessions usa i settings (workspace/provider/model/thinking) e crea+a
   }), {
     thtRunner: {
       ollamaEnsure: async () => ({ ok: true }),
+      searchPack: async () => {},
       sessionNew: async (o: any) => { sessionNewArg = o; return { id: "s1" }; },
       sessionList: async () => [{ id: "s1" }],
     } as any,
@@ -50,6 +51,7 @@ test("POST /sessions/:id/response inoltra al bridge (no error)", async () => {
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {
       ollamaEnsure: async () => ({ ok: true }),
+      searchPack: async () => {},
       sessionNew: async () => ({ id: "s1" }),
       sessionList: async () => [],
     } as any,
@@ -134,6 +136,7 @@ test("POST /sessions refuses with 503 when ollamaEnsure fails (no session create
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {
       ollamaEnsure: async () => ({ ok: false, stage: "model", error: "modello non installato" }),
+      searchPack: async () => {},
       sessionNew: async () => { createdCalled = true; return { id: "s1" }; },
     } as any,
     getSettings: () => ({ workspace: "psd" }) as any,
@@ -150,6 +153,7 @@ test("POST /sessions proceeds when ollamaEnsure succeeds", async () => {
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {
       ollamaEnsure: async (ws: string) => { ensureWs = ws; return { ok: true }; },
+      searchPack: async () => {},
       sessionNew: async () => ({ id: "s1" }),
     } as any,
     getSettings: () => ({ workspace: "psd" }) as any,
@@ -183,3 +187,59 @@ test("POST /sessions/:id/resume refuses with 503 when ollamaEnsure fails", async
   const res = await app.inject({ method: "POST", url: "/sessions/s1/resume" });
   expect(res.statusCode).toBe(503);
 });
+
+test("POST /runtime/prewarm returns 202 without awaiting readiness", async () => {
+  let workspace: string | undefined;
+  let finish!: (value: any) => void;
+  const pending = new Promise((resolve) => { finish = resolve; });
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    thtRunner: {} as any,
+    readiness: {
+      ensure: (ws: string) => { workspace = ws; return pending; },
+    } as any,
+    getSettings: () => ({ workspace: "psd" }) as any,
+  });
+  const res = await app.inject({ method: "POST", url: "/runtime/prewarm" });
+  expect(res.statusCode).toBe(202);
+  expect(res.json()).toEqual({ status: "warming" });
+  expect(workspace).toBe("psd");
+  finish({ ok: true });
+});
+
+test("POST /sessions returns after bridge attachment but starts only after retrieval", async () => {
+  let finishPack!: () => void;
+  const pack = new Promise<void>((resolve) => { finishPack = resolve; });
+  let bridgeAttached = false;
+  let started = false;
+  const bridge = {
+    onClientEvent: () => { bridgeAttached = true; },
+    emitClientEvent: () => {},
+  };
+  const runtime = { bridge } as any;
+  const mgr = {
+    createFor: () => runtime,
+    configure: async () => {},
+    start: () => {
+      expect(bridgeAttached).toBe(true);
+      started = true;
+    },
+    teardown: () => {},
+  } as any;
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    mgr,
+    thtRunner: {
+      ollamaEnsure: async () => ({ ok: true }),
+      sessionNew: async () => ({ id: "s-early" }),
+      searchPack: async () => pack,
+    } as any,
+    getSettings: () => ({ workspace: "psd" }) as any,
+  });
+
+  const res = await app.inject({ method: "POST", url: "/sessions", payload: { question: "q" } });
+  expect(res.json()).toEqual({ id: "s-early" });
+  expect(bridgeAttached).toBe(true);
+  expect(started).toBe(false);
+  finishPack();
+  await new Promise((resolve) => setImmediate(resolve));
+  expect(started).toBe(true);
+});