Load deployment config from /api/config on startup:
- src/config.js: loader with 3s timeout + hardcoded fallback
- src/hooks/useConfig.js: useConfig() and useFeature() hooks
- MapView.jsx: tile URL, attribution, center, zoom from config
- main.jsx: loads config before first render
Falls back to home profile defaults if backend unavailable.
No visible behavior change — infrastructure for future features.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>