chore: repo cleanup and prod sync tooling

- Remove stale deploy/docker-entrypoint.sh (Dockerfile copies root version)
- Remove scripts/seed.ts (superseded by seed.mjs)
- Add src/app/error.tsx and global-error.tsx (untracked error boundaries)
- Gitignore deploy/.prod/ for synced production configs
- Add scripts/sync-prod.ps1 to pull compose/env/Caddyfile from valhalla
- Add scripts/apply-compose.ps1 to push compose changes and restart services

.gitignore

@@ -49,5 +49,8 @@ tests/.auth/
 # Backups
 deploy/backups/data/
 
+# Production configs synced from server — never commit
+deploy/.prod/
+
 # Design handoff bundle (reference only, not committed)
 .design-tmp/