v0.9.0: in-app auto-updater, ship toggle split, stable entity IDs, performance fixes

New features:
- In-app auto-updater with confirmation dialog, manual download fallback,
  restart polling, and protected file safety net
- Ship layers split into 4 independent toggles (Military/Carriers, Cargo/Tankers,
  Civilian, Cruise/Passenger) with per-category counts
- Stable entity IDs using MMSI/callsign instead of volatile array indices
- Dismissible threat alert bubbles (session-scoped, survives data refresh)

Performance:
- GDELT title fetching is now non-blocking (background enrichment)
- Removed duplicate startup fetch jobs
- Docker healthcheck start_period 15s → 90s

Bug fixes:
- Removed fake intelligence assessment generator (OSINT-only policy)
- Fixed carrier tracker GDELT 429/TypeError crash
- Fixed ETag collision (full payload hash)
- Added concurrent /api/refresh guard

Contributors: @imqdcr (ship split + stable IDs), @csysp (dismissible alerts, PR #48)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Former-commit-id: a2c4c67da54345393f70a9b33b52e7e4fd6c049f

.gitignore

@@ -58,6 +58,8 @@ tmp/
 *.log
 *.tmp
 *.bak
+*.swp
+*.swo
 out.txt
 out_sys.txt
 rss_output.txt
@@ -75,7 +77,11 @@ backend/out_liveua.json
 frontend/server_logs*.txt
 frontend/cctv.db
 *.zip
+*.tar.gz
 .git_backup/
+coverage/
+.coverage
+dist/
 
 # Test files (may contain hardcoded keys)
 backend/test_*.py