fix(backend): check read-only 409 before the Ollama preflight on resume

backend/src/routes/sessions.ts

@@ -50,12 +50,12 @@ export function sessionRoutes(
   });
   app.post("/sessions/:id/resume", async (req, reply) => {
     const id = (req.params as any).id;
-    const ensure = await d.tht.ollamaEnsure(d.getSettings().workspace ?? "", d.ollamaEnsureTimeoutSec);
-    if (!ensure.ok) return reply.code(503).send({ error: ensure.error ?? "Ollama/embeddings non disponibili" });
     const manifest = (await d.tht.sessionShow(id)) as { status?: string; archived?: boolean } | null;
     if (manifest?.status === "finalized" || manifest?.archived) {
       return reply.code(409).send({ error: "sessione in sola lettura (finalizzata o archiviata)" });
     }
+    const ensure = await d.tht.ollamaEnsure(d.getSettings().workspace ?? "", d.ollamaEnsureTimeoutSec);
+    if (!ensure.ok) return reply.code(503).send({ error: ensure.error ?? "Ollama/embeddings non disponibili" });
     const rt = await d.mgr.resume(id, d.tht);
     rt.bridge.onClientEvent((e) => d.hub.publish(id, e.type, e));
     return reply.code(200).send({ id });

backend/test/routes-sessions.test.ts

@@ -152,6 +152,17 @@ test("POST /sessions proceeds when ollamaEnsure succeeds", async () => {
   expect(ensureWs).toBe("psd");
 });
 
+test("POST /sessions/:id/resume returns 409 for a read-only session without calling ollamaEnsure", async () => {
+  let ensureCalled = false;
+  const app = mutApp({
+    sessionShow: async () => ({ status: "finalized", archived: false }),
+    ollamaEnsure: async () => { ensureCalled = true; return { ok: false, error: "down" }; },
+  });
+  const res = await app.inject({ method: "POST", url: "/sessions/s1/resume" });
+  expect(res.statusCode).toBe(409);
+  expect(ensureCalled).toBe(false);
+});
+
 test("POST /sessions/:id/resume refuses with 503 when ollamaEnsure fails", async () => {
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {

docs/superpowers/specs/2026-06-29-ollama-ensure-design.md

@@ -103,9 +103,10 @@ and the start spawn behind a seam.
 The preflight runs **first**, before any session is created or resumed:
 - `POST /sessions`: `const r = await tht.ollamaEnsure(settings.workspace, timeout)`. If `!r.ok`
   → `reply.code(503).send({ error: r.error })` and **return** (do NOT call `sessionNew`/`spawnFor`).
-- `POST /sessions/:id/resume`: same preflight **before** the existing finalized/archived guard
+- `POST /sessions/:id/resume`: the finalized/archived guard runs **first** — a read-only session
-  and `mgr.resume`. On failure → 503, no spawn. (Uses the session's workspace — the current
+  is rejected with 409 without touching Ollama. The preflight runs **after** that guard and
-  configured/settings workspace, consistent with how resume resolves the session.)
+  **before** `mgr.resume`. On failure → 503, no spawn. (Uses the session's workspace — the
+  current configured/settings workspace, consistent with how resume resolves the session.)
 
 ### Config ([config.ts](../../../backend/src/config.ts))
 - `ollamaEnsureTimeoutMs: number` from `OLLAMA_ENSURE_TIMEOUT_MS` (default `60000`); passed to