test: lock in the app readiness gate with static, deterministic and real-stack probes (E00-S03-T06)

tests/health-endpoint.test.mjs

@@ -111,15 +111,23 @@ function reservePort() {
 /**
  * Boots the committed server source on `port`. Returns `{ child, stderr }`;
  * the child writes its stderr into the `stderr()` closure for diagnostics.
+ *
+ * The child boots WITHOUT `DATABASE_URL` (it is stripped from the inherited
+ * env): since E00-S03-T06 the health endpoint is the readiness probe, and the
+ * no-DATABASE_URL path is the one with no startup migration run to wait for —
+ * the server reports ready immediately, so this smoke test stays deterministic
+ * and exercises exactly the committed no-migration readiness path.
  */
 function bootServer(port) {
   const args =
     tsExecMode() === 'strip-types-flag'
       ? ['--experimental-strip-types', SERVER_SRC]
       : [SERVER_SRC];
+  const env = { ...process.env, PORT: String(port) };
+  delete env.DATABASE_URL;
   const child = spawn(process.execPath, args, {
     cwd: REPO_ROOT,
-    env: { ...process.env, PORT: String(port) },
+    env,
     stdio: ['ignore', 'ignore', 'pipe'],
   });
   let stderr = '';