feat(MemberPlayInterest): implement play interest management for members

- Added new endpoints to get and set member play interests in the memberController.
- Integrated MemberPlayInterest model into the application, establishing relationships with Member and Club models.
- Updated memberRoutes to include routes for managing member play interests.
- Enhanced memberService to handle play interest retrieval and updates.
- Updated localization files to include new terms related to member play interests.
- Refactored server.js to include MemberPlayInterest in the synchronization process.

backend/migrations/20260415_create_member_play_interest.sql

@@ -0,0 +1,16 @@
+-- Halbserienbasierte Spielinteressen (pro Mitglied, Club, Saison und Halbserie)
+
+CREATE TABLE IF NOT EXISTS `member_play_interest` (
+  `id` INT NOT NULL AUTO_INCREMENT,
+  `club_id` INT NOT NULL,
+  `member_id` INT NOT NULL,
+  `season_id` INT NOT NULL,
+  `lineup_half` ENUM('first_half', 'second_half') NOT NULL,
+  `interested` TINYINT(1) NOT NULL DEFAULT 1,
+  `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `updated_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  PRIMARY KEY (`id`),
+  UNIQUE KEY `uniq_member_play_interest_half` (`club_id`, `member_id`, `season_id`, `lineup_half`),
+  KEY `idx_member_play_interest_member` (`member_id`),
+  KEY `idx_member_play_interest_season` (`season_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;