Cleanup code and prepare for AI usage

docs/googlecalendar.md

@@ -0,0 +1,29 @@
+# googlecalendar — Google Calendar Integration
+
+Manages matchday deadline events in Google Calendar. Each matchday can have up to 3 delivery deadlines (1st, 2nd, 3rd chance).
+
+## Classes
+
+### GoogleCalendarConnector
+Sets up the Google Calendar API service using a service account.
+
+- Reads service account credentials from `tippliga-4e0def9ef447.json` (classpath resource)
+- Uses `CalendarScopes.CALENDAR` scope
+- Returns authenticated `com.google.api.services.calendar.Calendar` service
+
+### CalendarConfigProvider
+Reads calendar ID and URL from `Google_Calendar_Config.json` resource. Currently hardcoded to league 1.
+
+### TippligaGoogleEventManager
+CRUD operations for matchday deadline events.
+
+- `createOrUpdateEventsForMatchday(matchday)` — creates/updates up to 3 events per matchday
+- `createNewEvent()` / `updateEvent()` / `deleteEvent()` — individual event operations
+- `deleteAllEvents(season)` — wipe all events for a season
+- `updateAllMatchdays(matchdays)` — batch update; automatically deletes events for removed delivery dates
+
+Event details:
+- **Summary**: `"Tippliga Spieltag N tippen!"` (or custom matchday name)
+- **Description**: season, league, matchday, delivery deadline number
+- **Location**: `https://tippliga-wuerzburg.de/app.php/football/bet`
+- **Time**: delivery deadline datetime, Europe/Berlin timezone