feat(db): add tile-region mapping datasets

Add regions.csv and tile_region_mapping.csv to provide region metadata
and tile-to-region relationships. Update server initialization and auth
routes to integrate the new data, and expand .env.example with related
configuration variables.

This makes region information queryable and prepares scripts for
seeding/import.

.env.example

@@ -11,3 +11,15 @@ JWT_SECRET="your-secret-key"
 GOOGLE_CLIENT_ID="your-google-client-id"
 GOOGLE_CLIENT_SECRET="your-google-client-secret"
 GOOGLE_CALLBACK_URL="http://localhost:3000/auth/google/callback"
+
+# Cookie configuration
+COOKIE_SECURE=true
+COOKIE_SAME_SITE=Strict
+# Optional: set to your public domain if needed (e.g., example.com)
+COOKIE_DOMAIN=
+
+# Bot protection
+TURNSTILE_SECRET_KEY="your-turnstile-secret"
+# Development bypass token (set to empty in production)
+TURNSTILE_BYPASS_TOKEN="turnstile-disabled"
+