Adds `VerifyApiKey` middleware protecting all API routes with `X-Api-Key` header validation. Wraps `/api/stations`, `/api/stats/searches`, and `/api/prediction` in throttled middleware group (60 req/min). Updates StationSearchTest to use `RefreshDatabase`, adds `meta` assertion checks, and validates `fuel_type` in HTTP request assertions. Removes auth routes from API docs and replaces with API key authentication instructions. Adds `api_secret_key` config option.
Extends NearbyStationsRequest to accept `postcode` (full or outcode) as an alternative to lat/lng. PostcodeService resolves it via postcodes.io and falls through to coordinates. Also adds SearchResource to the Filament admin panel for viewing logged search activity with fuel type filter and price/distance stats columns. Includes SQLite GREATEST/LEAST function polyfills in AppServiceProvider for test compatibility.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
