fix: replace unicode characters and fix finalize-restore endpoint

Style check fixes:
- Replace unicode box-drawing characters with ASCII (|-- instead of ├──)
- Replace emoji status markers with [OK]/[FAIL]/[WARN] tags
- Replace arrows (→ with ->, ↔ with <->) and em-dashes (— with --)
- Add venv-quick to excluded directories in check script
- Exclude darkwing report files (findings.sarif, report.md)

Backup finalization fix:
- Fix finalize-restore endpoint to not claim the upgrade sentinel
- Endpoint now checks for pending upgrade and returns {queued: true}
- Leaves UPGRADE_SENTINEL for background watcher to claim and process
- Prevents inline Alembic runs that can outlast request timeout

Claude Code context:
- Add .claude/ directory with INDEX.md and QUICK-REFERENCE.md
- Add CLAUDE.md with project overview and conventions
- Helps Claude Code understand project structure and rules

Fixes failing test: test_the_endpoint_does_not_run_the_upgrade_itself
Fixes naming/style CI check violations

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

DEPLOY-TO-VM.md

@@ -53,13 +53,13 @@ cd C:\shopdb
 
 ## What the Script Does
 
-1. ✅ Checks Docker Desktop is running
-2. ✅ Creates .env from template
-3. ✅ Builds frontend (if needed)
-4. ✅ Builds Docker images (2-3 minutes, offline packages)
-5. ✅ Starts all services (db + api + backup)
-6. ✅ Runs database migrations
-7. ✅ Sets admin password
+1. [OK] Checks Docker Desktop is running
+2. [OK] Creates .env from template
+3. [OK] Builds frontend (if needed)
+4. [OK] Builds Docker images (2-3 minutes, offline packages)
+5. [OK] Starts all services (db + api + backup)
+6. [OK] Runs database migrations
+7. [OK] Sets admin password
 
 ## Manual Deployment (Alternative)
 
@@ -140,7 +140,7 @@ New-NetFirewallRule -DisplayName "ShopDB" -Direction Inbound -LocalPort 5001 -Pr
 
 **SSL certificate warnings:**
 - Normal for self-signed certs
-- Click "Advanced" → "Proceed to localhost (unsafe)"
+- Click "Advanced" -> "Proceed to localhost (unsafe)"
 
 ## Stop/Start
 
@@ -169,9 +169,9 @@ docker compose -f docker-compose.prebuilt.yml -f docker-compose.backup.yml up -d
 ## Offline Deployment Notes
 
 **This deployment works completely offline** because:
-- ✅ Frontend pre-built and checked into repo
-- ✅ Restic binary pre-downloaded (8.6MB in repo)
-- ✅ No npm/pip downloads during Docker build
-- ✅ All dependencies baked into images
+- [OK] Frontend pre-built and checked into repo
+- [OK] Restic binary pre-downloaded (8.6MB in repo)
+- [OK] No npm/pip downloads during Docker build
+- [OK] All dependencies baked into images
 
 Perfect for air-gapped or restricted network environments!