debug(vtex): probe isolate reuse + per-request timing

vtex/server/main.ts

@@ -19,6 +19,33 @@ const runtime = withRuntime<Env, typeof StateSchema>({
   tools,
 });
 
+// DEBUG PROBE — temporary. If `requestCount` increments across requests, the
+// isolate is being reused and module-scope caches in @decocms/runtime should
+// stick. If it always reads `1`, Workers is spawning a fresh isolate per
+// request and the runtime's tools/list cache can never hit. Logs are printed
+// before and after the runtime fetch, with timing.
+const isolateBootedAt = Date.now();
+let requestCount = 0;
+
 export default {
-  fetch: runtime.fetch,
+  fetch: async (req: Request, env: Env, ctx: ExecutionContext) => {
+    const myReq = ++requestCount;
+    const t0 = Date.now();
+    console.log(
+      `[vtex-probe] req#${myReq} isolateAge=${t0 - isolateBootedAt}ms url=${new URL(req.url).pathname}`,
+    );
+    try {
+      const res = await runtime.fetch(req, env, ctx);
+      console.log(
+        `[vtex-probe] req#${myReq} done status=${res.status} ms=${Date.now() - t0}`,
+      );
+      return res;
+    } catch (err) {
+      console.log(
+        `[vtex-probe] req#${myReq} threw after ${Date.now() - t0}ms`,
+        err,
+      );
+      throw err;
+    }
+  },
 };