🗃️ refactor: Separate Tool Cache Namespace for Blue/Green Deployments (#11738)

* 🔧 refactor: Introduce TOOL_CACHE for isolated caching of tools

- Added TOOL_CACHE key to CacheKeys enum for managing tool-related cache.
- Updated various services and controllers to utilize TOOL_CACHE instead of CONFIG_STORE for better separation of concerns in caching logic.
- Enhanced .env.example with comments on using in-memory cache for blue/green deployments.

* 🔧 refactor: Update cache configuration for in-memory storage handling

- Enhanced the handling of `FORCED_IN_MEMORY_CACHE_NAMESPACES` in `cacheConfig.ts` to default to `CONFIG_STORE` and `APP_CONFIG`, ensuring safer blue/green deployments.
- Updated `.env.example` with clearer comments regarding the usage of in-memory cache namespaces.
- Improved unit tests to validate the new default behavior and handling of empty strings for cache namespaces.

.env.example

@@ -748,8 +748,10 @@ HELP_AND_FAQ_URL=https://librechat.ai
 # REDIS_PING_INTERVAL=300
 
 # Force specific cache namespaces to use in-memory storage even when Redis is enabled
-# Comma-separated list of CacheKeys (e.g., ROLES,MESSAGES)
-# FORCED_IN_MEMORY_CACHE_NAMESPACES=ROLES,MESSAGES
+# Comma-separated list of CacheKeys
+# Defaults to CONFIG_STORE,APP_CONFIG so YAML-derived config stays per-container (safe for blue/green deployments)
+# Set to empty string to force all namespaces through Redis: FORCED_IN_MEMORY_CACHE_NAMESPACES=
+# FORCED_IN_MEMORY_CACHE_NAMESPACES=CONFIG_STORE,APP_CONFIG
 
 # Leader Election Configuration (for multi-instance deployments with Redis)
 # Duration in seconds that the leader lease is valid before it expires (default: 25)