feat(redis): integrate Redis for job queue management and persistent storage

.env.example

@@ -67,6 +67,9 @@ DATABASE_TYPE=sqlite
 # POSTGRES_PASSWORD=your_password_here
 # POSTGRES_DB=discord_bot
 
+# Redis Configuration (queue + persistent KV store)
+# REDIS_URL=redis://localhost:6379
+
 # PostgreSQL Connection Pool Configuration
 # POSTGRES_POOL_MIN=2
 # POSTGRES_POOL_MAX=10