M4 handover: coordinate fixes, detector registry, deploy v2, YOLOv8s, identity lifecycle

- Fix swift_pose/swift_ocr Y-flip bugs (BUG-003~006)
- Add heuristic_scene module + post-processing trigger (replaces Places365)
- YOLOv5nu → YOLOv8s CoreML (+33% detections, +390% scene indicators)
- Per-table SQL export (split 4.7GB single file → 478MB max per table)
- Version/build check in deploy.sh (compare /health vs file_info.json)
- Add file_uuid column to identities table + backfill
- Identity pre-clean step in deploy (avoids UNIQUE conflicts on re-deploy)
- Stranger_xxx naming fix with UUID context
- Add DETECTOR_REGISTRY.md (25 detectors), DETECTOR_SELECTION_SOP.md
- Update SPATIAL_COORDINATE_REGISTRY.md (P layer, 6-layer architecture)
- New IDENTITY_LIFECYCLE.md
- M4 response docs for deploy_script_fix and 111614 test report

src/api/server.rs

@@ -72,6 +72,7 @@ fn get_uptime_ms() -> u64 {
 struct HealthResponse {
     status: String,
     version: String,
+    build_git_hash: String,
     uptime_ms: u64,
 }
 
@@ -369,6 +370,7 @@ pub struct AppState {
 struct DetailedHealthResponse {
     status: String,
     version: String,
+    build_git_hash: String,
     uptime_ms: u64,
     services: ServiceHealth,
 }
@@ -408,6 +410,7 @@ async fn health(State(state): State<AppState>) -> Json<HealthResponse> {
     Json(HealthResponse {
         status: status.to_string(),
         version: env!("BUILD_VERSION").to_string(),
+        build_git_hash: env!("BUILD_GIT_HASH").to_string(),
         uptime_ms: get_uptime_ms(),
     })
 }
@@ -431,6 +434,7 @@ async fn health_detailed(State(state): State<AppState>) -> Json<DetailedHealthRe
     Json(DetailedHealthResponse {
         status: overall_status.to_string(),
         version: env!("BUILD_VERSION").to_string(),
+        build_git_hash: env!("BUILD_GIT_HASH").to_string(),
         uptime_ms: get_uptime_ms(),
         services: ServiceHealth {
             postgres,