Implement cross-club friendly match concept with invitations and shared matches

- Added controllers for handling friendly match invitations and shared matches.
- Created migration scripts for `friendly_match_invitation` and `friendly_match_shared` tables.
- Developed models for `FriendlyMatchInvitation` and `FriendlyMatchShared`.
- Established routes for managing invitations and shared matches.
- Implemented services for business logic related to invitations and shared matches.
- Documented the concept plan for the new feature including API endpoints and data models.

backend/routes/friendlyMatchInvitationRoutes.js

@@ -0,0 +1,20 @@
+import express from 'express';
+import {
+  acceptFriendlyMatchInvitation,
+  createFriendlyMatchInvitation,
+  declineFriendlyMatchInvitation,
+  listIncomingFriendlyMatchInvitations,
+  listOutgoingFriendlyMatchInvitations,
+} from '../controllers/friendlyMatchInvitationController.js';
+import { authenticate } from '../middleware/authMiddleware.js';
+import { authorize } from '../middleware/authorizationMiddleware.js';
+
+const router = express.Router();
+
+router.post('/:clubId', authenticate, authorize('schedule', 'write'), createFriendlyMatchInvitation);
+router.get('/:clubId/incoming', authenticate, authorize('schedule', 'read'), listIncomingFriendlyMatchInvitations);
+router.get('/:clubId/outgoing', authenticate, authorize('schedule', 'read'), listOutgoingFriendlyMatchInvitations);
+router.post('/:clubId/:invitationId/accept', authenticate, authorize('schedule', 'write'), acceptFriendlyMatchInvitation);
+router.post('/:clubId/:invitationId/decline', authenticate, authorize('schedule', 'write'), declineFriendlyMatchInvitation);
+
+export default router;

backend/routes/friendlyMatchSharedRoutes.js

@@ -0,0 +1,20 @@
+import express from 'express';
+import {
+  deleteSharedFriendlyMatch,
+  findSharedFriendlyMatches,
+  listSharedFriendlyMatches,
+  updateSharedFriendlyMatch,
+  updateSharedFriendlyMatchPlayers,
+} from '../controllers/friendlyMatchSharedController.js';
+import { authenticate } from '../middleware/authMiddleware.js';
+import { authorize } from '../middleware/authorizationMiddleware.js';
+
+const router = express.Router();
+
+router.get('/find', authenticate, authorize('schedule', 'read'), findSharedFriendlyMatches);
+router.get('/shared/:clubId', authenticate, authorize('schedule', 'read'), listSharedFriendlyMatches);
+router.put('/shared/:clubId/:matchId', authenticate, authorize('schedule', 'write'), updateSharedFriendlyMatch);
+router.patch('/shared/:clubId/:matchId/players', authenticate, authorize('schedule', 'write'), updateSharedFriendlyMatchPlayers);
+router.delete('/shared/:clubId/:matchId', authenticate, authorize('schedule', 'write'), deleteSharedFriendlyMatch);
+
+export default router;