Enable Doctrine L2 cache and add Redis cache pools
Doctrine Second Level Cache (NONSTRICT_READ_WRITE) on:
- Event, User, Category, Billet, BilletDesign
- Default region: 1h TTL, short_lived region: 5min TTL
Redis cache pools added:
- app.cache.events (30min) — for event listings
- app.cache.homepage (5min) — for homepage data
- doctrine.result_cache_pool — DQL result cache via Redis
- doctrine.system_cache_pool — metadata/query cache
All pools backed by Redis DB 2. Reduces DB queries significantly
for read-heavy pages (event listings, user profiles, categories).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>