feat(pre-push-safety-net): establish shared push and engine contracts

.kiro/specs/pre-push-safety-net/spec.json

@@ -1,7 +1,7 @@
 {
   "feature_name": "pre-push-safety-net",
   "created_at": "2026-09-12T15:35:00Z",
-  "updated_at": "2026-09-12T16:20:40.814596Z",
+  "updated_at": "2026-09-12T17:21:05.783007Z",
   "language": "en",
   "phase": "implementation",
   "approvals": {
@@ -50,5 +50,16 @@
     "executable_subtasks": 27,
     "requirements_covered": 35,
     "record": "task-review.md"
+  },
+  "implementation_progress": {
+    "completed_tasks": [
+      "1.1",
+      "1.2",
+      "1.3",
+      "1.4"
+    ],
+    "remaining_tasks": 23,
+    "verification_record": "implementation-group-1.md",
+    "next_group": 2
   }
 }