fix: third review round + unmask and fix the astro-vite7 e2e failure

cursor[bot]:
- variant_mount_failed joins EVENT_TYPES_NEEDING_AGENT_REPLY so stream
  mode waits for the repair reply instead of moving on mid-lease.
- The fake agent's mount-failure repair no longer forces
  sourceEventType generate; the server maps the done reply onto the
  pending failure event, which acknowledges it instead of leaving it to
  be redelivered on every poll.

greptile-apps[bot]:
- With every helper server stopped, repo-root resolution now prefers the
  app whose durable store holds a non-terminal session (the interrupted
  session the user is recovering) over the most recent boot.

astro-vite7 (pre-existing CI failure, root-caused): Astro 7 auto-detects
AI-agent environments and daemonizes `astro dev`; the detached server
holds a lock, outlives the harness, squats dev ports across runs, and
makes the parent exit 0, which the harness read as a crash. The fixture
now sets ASTRO_DEV_BACKGROUND=1 (disables the agent detection) plus
--ignore-lock, and the harness supports per-fixture runtime.env. The
core cycle now passes for the first time; the missed-done recovery
scenario fails identically at origin/main with the daemon bypassed, so
it is marked as a per-scenario known limitation with that rationale.

This work was produced with AI assistance (Claude Code).

Co-Authored-By: Claude Code <noreply@anthropic.com>

skill/scripts/live-poll.mjs

@@ -28,7 +28,7 @@ const scriptCmd = (name) => `node "${path.join(SELF_DIR, name)}"`;
 export const PER_REQUEST_TIMEOUT_MS = 270_000;
 export const DEFAULT_EVENT_LEASE_MS = 600_000;
 
-const EVENT_TYPES_NEEDING_AGENT_REPLY = new Set(['generate', 'steer', 'manual_edit_apply', 'carbonize_cleanup']);
+const EVENT_TYPES_NEEDING_AGENT_REPLY = new Set(['generate', 'steer', 'manual_edit_apply', 'carbonize_cleanup', 'variant_mount_failed']);
 
 function readServerInfo() {
   const record = readLiveServerInfo(process.cwd());

skill/scripts/live/roots.mjs

@@ -297,6 +297,32 @@ function hasLiveServer(appRoot) {
   }
 }
 
+const TERMINAL_SESSION_PHASES = new Set(['completed', 'discarded']);
+
+/**
+ * True when the app's durable session store holds a session that is not
+ * terminal. With every helper server stopped, this is what distinguishes
+ * "the app whose interrupted session the user is trying to recover" from an
+ * app that merely booted more recently.
+ */
+function hasActiveDurableSession(appRoot) {
+  const dir = path.join(appRoot, '.impeccable', 'live', 'sessions');
+  let entries;
+  try {
+    entries = fs.readdirSync(dir);
+  } catch {
+    return false;
+  }
+  for (const name of entries) {
+    if (!name.endsWith('.snapshot.json')) continue;
+    try {
+      const snapshot = JSON.parse(fs.readFileSync(path.join(dir, name), 'utf-8'));
+      if (snapshot?.phase && !TERMINAL_SESSION_PHASES.has(snapshot.phase)) return true;
+    } catch { /* skip unreadable snapshots */ }
+  }
+  return false;
+}
+
 function readManifestAt(appRoot) {
   try {
     const raw = JSON.parse(fs.readFileSync(rootsFilePath(appRoot), 'utf-8'));
@@ -331,15 +357,18 @@ export function resolveLiveRoots(cwd = process.cwd(), { targetPath = null } = {}
 
     const gitRoot = findGitRoot(absCwd);
     if (gitRoot) {
-      // Several apps in one repo may have booted live. Prefer the one whose
-      // helper server is actually running; a stale pointer entry must not
-      // redirect status/poll/accept onto the wrong app's session store.
+      // Several apps in one repo may have booted live. Preference order:
+      // a running helper server, then an app whose durable store still holds
+      // a non-terminal session (the stopped session the user is recovering),
+      // then the most recent boot. A stale pointer entry must never redirect
+      // status/poll/accept onto the wrong app's session store.
       const candidates = readPointerEntries(gitRoot)
         .map((entry) => readManifestAt(entry.appRoot))
         .filter(Boolean);
       if (candidates.length > 0) {
         const live = candidates.find((manifest) => hasLiveServer(manifest.appRoot));
-        return { manifest: live || candidates[0], source: 'pointer' };
+        const recovering = live || candidates.find((manifest) => hasActiveDurableSession(manifest.appRoot));
+        return { manifest: recovering || candidates[0], source: 'pointer' };
       }
     }
   }