S00-012: Record blocked task and remediation handoff

Changes: Preserve incomplete work and blocker metadata for S00-012. This checkpoint does not mark implementation accepted.
Validation: Session ended with status blocked.
Blocker: Submit-transition descendant regression fails: repeated stop_process_tree after parent reap raises EPERM at os.killpg; launch OSError handling then attempts invalid escalation from review state.

Task: S00-012
Agent: auto-ci-cd-28868645424b
Role: ci-cd
Action: claim
Status: blocked

Task title: Fix runner prompt delivery after partial stdin timeout

planning/tasks.json

@@ -685,7 +685,8 @@
       "depends_on": [
         "S00-001",
         "S00-011",
-        "S00-013"
+        "S00-013",
+        "S00-014"
       ],
       "requirements": [
         "NFR-007"
@@ -777,6 +778,61 @@
       ],
       "context_budget_chars": 48000
     },
+    {
+      "id": "S00-014",
+      "stage": "S00",
+      "kind": "blocker",
+      "root_task": "S00-002",
+      "blocker_depth": 2,
+      "unblocks": [
+        "S00-012"
+      ],
+      "role": "ci-cd",
+      "reviewer_role": "qa",
+      "title": "Fix repeated runner cleanup after a submitted parent is reaped",
+      "outcome": "Reliable repeated lifecycle cleanup after submit with a reaped parent and SIGTERM-ignoring descendant, preserving actual process-tree termination and valid workflow state.",
+      "depends_on": [
+        "S00-001",
+        "S00-011",
+        "S00-013"
+      ],
+      "requirements": [
+        "NFR-007"
+      ],
+      "scope": [
+        "scripts/runner.py",
+        "tests/tooling/test_automation.py"
+      ],
+      "inputs": [
+        "docs/WEB_PROFILE.md",
+        "docs/ARCHITECTURE.md",
+        "docs/CONTRACTS.md",
+        "docs/TESTING.md",
+        "roles/orchestrator.md",
+        "docs/decisions/README.md",
+        "state/blockers/S00-012.md",
+        "state/blockers/S00-014.md"
+      ],
+      "spec_sections": [],
+      "ui_sections": [],
+      "steps": [
+        "Read S00-012 evidence and preserved descendant regressions.",
+        "Reproduce repeated cleanup EPERM in the supplied execution harness without launching a model.",
+        "Correct only the repeated-cleanup lifecycle failure; retain fail-closed handling for inaccessible live descendants and terminal/deadline monitoring.",
+        "Run descendant, delayed stdin and existing lifecycle checks plus make check; record evidence and submit."
+      ],
+      "acceptance": [
+        "Submit-transition descendant regression completes without invalid escalation or delayed source writes.",
+        "Timeout and terminal-transition paths terminate descendants, including SIGTERM-ignoring children.",
+        "Repeated cleanup does not hide a failure to terminate a live process; stdin delivery and prompt budgets remain intact."
+      ],
+      "checks": [
+        "Both preserved descendant regressions.",
+        "Delayed-reader UTF-8/EOF, timeout, transition, scope and fresh-session runner checks.",
+        "make check"
+      ],
+      "context_budget_chars": 48000
+    },
     {
       "id": "S00-010",
       "stage": "S00",