chore: remove obsolete Android app configuration files

- Deleted build.gradle.kts, gradle.properties, and gradlew files as part of the cleanup process.
- Removed local.properties and various generated files from the .gradle directory to streamline the project structure.
- Cleared out unnecessary build artifacts and intermediate files to improve project maintainability.

backend/server.js

@@ -13,8 +13,8 @@ import {
   DiaryNote, DiaryTag, MemberDiaryTag, DiaryDateTag, DiaryMemberNote, DiaryMemberTag,
   PredefinedActivity, PredefinedActivityImage, DiaryDateActivity, DiaryMemberActivity, Match, League, Team, ClubTeam, ClubTeamMember, TeamDocument, Group,
   GroupActivity, Tournament, TournamentGroup, TournamentMatch, TournamentResult,
-  TournamentMember, Accident, UserToken, OfficialTournament, OfficialCompetition, OfficialCompetitionMember, MyTischtennis, ClickTtAccount, MyTischtennisUpdateHistory, MyTischtennisFetchLog, ApiLog, MemberTransferConfig, MemberContact, MemberTtrHistory, MemberPlayInterest
-  , MemberOrder, MemberOrderHistory, MemberGroupPhoto
+  TournamentMember, Accident, UserToken, OfficialTournament, OfficialCompetition, OfficialCompetitionMember, MyTischtennis, ClickTtAccount, MyTischtennisUpdateHistory, MyTischtennisFetchLog, ApiLog, MemberTransferConfig, MemberContact, MemberTtrHistory, MemberPlayInterest,
+  MemberOrder, MemberOrderHistory, MemberGroupPhoto, BillingTemplate, BillingTemplateField, BillingRun, BillingDocument, BillingDocumentValue, BillingUserSetting
 } from './models/index.js';
 import authRoutes from './routes/authRoutes.js';
 import clubRoutes from './routes/clubRoutes.js';
@@ -57,6 +57,7 @@ import trainingGroupRoutes from './routes/trainingGroupRoutes.js';
 import trainingTimeRoutes from './routes/trainingTimeRoutes.js';
 import memberOrderRoutes from './routes/memberOrderRoutes.js';
 import memberGroupPhotoRoutes from './routes/memberGroupPhotoRoutes.js';
+import billingRoutes from './routes/billingRoutes.js';
 import schedulerService from './services/schedulerService.js';
 import { requestLoggingMiddleware } from './middleware/requestLoggingMiddleware.js';
 import HttpError from './exceptions/HttpError.js';
@@ -166,6 +167,7 @@ const SEO_NOINDEX_PREFIXES = [
   '/member-transfer-settings',
   '/personal-settings',
   '/orders',
+  '/billing',
 ];
 
 function normalizeSeoPath(pathname = '/') {
@@ -302,6 +304,7 @@ app.use('/api/training-groups', trainingGroupRoutes);
 app.use('/api/training-times', trainingTimeRoutes);
 app.use('/api/member-orders', memberOrderRoutes);
 app.use('/api/member-group-photos', memberGroupPhotoRoutes);
+app.use('/api/billing', billingRoutes);
 
 // Middleware für dynamischen kanonischen Tag (vor express.static)
 const setCanonicalTag = (req, res, next) => {
@@ -549,6 +552,12 @@ app.use((err, req, res, next) => {
     await safeSync(MemberPlayInterest);
     await safeSync(MemberOrder);
     await safeSync(MemberOrderHistory);
+    await safeSync(BillingTemplate);
+    await safeSync(BillingTemplateField);
+    await safeSync(BillingRun);
+    await safeSync(BillingDocument);
+    await safeSync(BillingDocumentValue);
+    await safeSync(BillingUserSetting);
     await safeSync(ClubTeam);
     await safeSync(TeamDocument);