fix(api): usage and keys (#2092)

Integrated into release/v3.8.0

.env.example

@@ -54,6 +54,12 @@ STORAGE_ENCRYPTION_KEY_VERSION=v1
 # Default: false (backups enabled)  |  Set true to skip backup on every restart.
 DISABLE_SQLITE_AUTO_BACKUP=false
 
+# ── Redis (Rate Limiting) ──
+# Redis connection URL for the rate limiter backend.
+# Used by: src/shared/utils/rateLimiter.ts
+# Default: redis://localhost:6379 (or redis://redis:6379 in Docker)
+REDIS_URL=redis://localhost:6379
+
 
 # ═══════════════════════════════════════════════════════════════════════════════
 # 3. NETWORK & PORTS