feat: harden runtime readiness and session workflow

backend/src/app.ts

@@ -11,6 +11,7 @@ import { metaRoutes, type ListModelsFn } from "./routes/meta.js";
 import { settingsRoutes, effectiveSettings } from "./routes/settings.js";
 import { createPiModelLister } from "./pi/list-models.js";
 import { loadSettings, type Settings } from "./settings/settings-store.js";
+import { ReadinessManager } from "./runtime/readiness-manager.js";
 
 export interface BuildAppDeps {
   thtRunner?: ThtRunner;
@@ -18,6 +19,7 @@ export interface BuildAppDeps {
   spawnFn?: () => any;
   listModels?: ListModelsFn;
   getSettings?: () => Settings;
+  readiness?: ReadinessManager;
 }
 
 export function buildApp(config: AppConfig, deps?: BuildAppDeps): FastifyInstance {
@@ -38,6 +40,10 @@ export function buildApp(config: AppConfig, deps?: BuildAppDeps): FastifyInstanc
   });
   const mgr = deps?.mgr ?? new PiProcessManager(config, deps?.spawnFn ? { spawnFn: deps.spawnFn } : undefined);
   const hub = new SseHub();
+  const readiness = deps?.readiness ?? new ReadinessManager(
+    tht as ThtRunner,
+    Math.round(config.ollamaEnsureTimeoutMs / 1000),
+  );
 
   const listModels = deps?.listModels ?? createPiModelLister(config);
   const getSettings = deps?.getSettings ?? (() => effectiveSettings(config, loadSettings(config)));
@@ -50,8 +56,7 @@ export function buildApp(config: AppConfig, deps?: BuildAppDeps): FastifyInstanc
   });
   app.get("/health", async () => ({ status: "ok" }));
   sessionRoutes(app, {
-    mgr, tht: tht as ThtRunner, hub, getSettings,
-    ollamaEnsureTimeoutSec: Math.round(config.ollamaEnsureTimeoutMs / 1000),
+    mgr, tht: tht as ThtRunner, hub, getSettings, readiness,
   });
   sqlRoutes(app, { tht: tht as ThtRunner });
   metaRoutes(app, { harnessDir: config.harnessDir, listModels });