T01: core infrastructure + auth + multi-tenant + RLS

- 10 models: tenants, users, user_tenants, roles, sessions, audit_log, deletion_log, notifications, password_reset_tokens, api_tokens
- Session-based auth (Redis + PostgreSQL audit trail)
- Multi-tenant with ORM-level filtering + PostgreSQL RLS (set_config)
- RBAC with roles/permissions + field-level permissions
- CSRF protection via Origin header validation
- Auth rate limiting (Redis counters with TTL)
- CORS with explicit origins (no wildcard)
- Health endpoint (no auth required)
- Notification service + audit log middleware
- 29 tests, 26 ACs, all passing
- Coverage: 62% (infrastructure modules pending coverage in later tasks)

.env

@@ -1,8 +1,6 @@
-AUTH_SECRET=test-secret-with-at-least-thirty-two-characters-for-development
-DATABASE_URL=sqlite+aiosqlite:///./dev.db
-JWT_ALGORITHM=HS256
-JWT_EXPIRY_HOURS=24
-BCRYPT_ROUNDS=4
-CORS_ORIGINS=http://localhost:5500,http://localhost:8000
+DATABASE_URL=postgresql+asyncpg://leocrm:leocrm@localhost:5432/leocrm
+REDIS_URL=redis://localhost:6379/0
 ENVIRONMENT=development
 LOG_LEVEL=INFO
+BCRYPT_ROUNDS=12
+CORS_ORIGINS=http://localhost:5173,http://localhost:3000