spec(ai-service-plane): design for review; requirements approved

Package src/openultrasast/plane/: manifests (ax kinds + Run), a reconciler under
500 lines with persisted status and resume, an ax-contract runner, budget metering,
and task entrypoints. First increment: repo-facts (source-only callers, no model),
verify (the batched hunt with callers in the prompt, per-unit resume), agree.
Measurement on the 46-candidate set against the recorded batched check.

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo

.kiro/specs/ai-service-plane/spec.json

@@ -1,16 +1,16 @@
 {
   "feature_name": "ai-service-plane",
   "created_at": "2026-09-29T15:40:00Z",
-  "updated_at": "2026-09-29T15:40:00Z",
+  "updated_at": "2026-09-29T16:05:00Z",
   "language": "en",
-  "phase": "requirements",
+  "phase": "design",
   "approvals": {
     "requirements": {
       "generated": true,
-      "approved": false
+      "approved": true
     },
     "design": {
-      "generated": false,
+      "generated": true,
       "approved": false
     },
     "tasks": {