Phase 9: division/season tracking, club customization, pack history, notifications

- GET /division returns live season stats (points, record, promotion threshold)
- PUT /club allows updating club name and manager_name
- GET /packs/history returns opened packs with full card definitions
- GET /notifications dynamically surfaces completed objectives, expiring loans, season end
- Club model gains manager_name column (migration 0006 already added it)
- Pack model gains opened_cards and opened_at; pack SELECT queries updated
- 9 new integration tests — all 45 pass, clippy clean

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/mod.rs

@@ -1,11 +1,13 @@
 pub mod auth;
 pub mod cards;
 pub mod club;
+pub mod division;
 pub mod draft;
 pub mod events;
 pub mod health;
 pub mod market;
 pub mod matches;
+pub mod notifications;
 pub mod objectives;
 pub mod packs;
 pub mod profile;