docs: mark scheduler-dispatch-commit tasks complete; add parked commit-batch-window spec

scheduler-dispatch-commit's 5 parent tasks were already fully implemented
(all subtasks checked); this rolls up the parent checkboxes to match.
commit-batch-window is a new spec, requirements-only, explicitly parked
(not actively pursued) pending a dedicated future session.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y4M5MJM2zK6nU43da267Ku

.kiro/specs/commit-batch-window/spec.json

@@ -0,0 +1,24 @@
+{
+  "feature_name": "commit-batch-window",
+  "created_at": "2026-08-31T14:07:43Z",
+  "updated_at": "2026-08-31T14:20:00Z",
+  "language": "en",
+  "phase": "initialized",
+  "approvals": {
+    "requirements": {
+      "generated": false,
+      "approved": false
+    },
+    "design": {
+      "generated": false,
+      "approved": false
+    },
+    "tasks": {
+      "generated": false,
+      "approved": false
+    }
+  },
+  "ready_for_implementation": false,
+  "sibling_specs": ["scheduler-dispatch-commit", "job-array-single-wal-record", "worker-rejoin-resync"],
+  "note": "Parked/tracked, not actively being pursued. Originally scoped narrowly as job-dispatch-commit-batching; broadened (2026-08-31, same session) to a general time-windowed batch-commit facility for ANY WAL-worthy fact needing a durability-gated external side effect, not just job dispatch -- job dispatch remains the motivating first use case. User assessed this as a substantial cross-cutting change (core commit pipeline, latency/throughput tradeoffs, hook/notification timing, soak-level correctness verification), not a small project. Revisit in a dedicated future session."
+}