🔀 feat: update OpenRouter with new Reasoning config (#11993)

* fix: Update OpenRouter reasoning handling in LLM configuration

- Modified the OpenRouter configuration to use a unified `reasoning` object instead of separate `reasoning_effort` and `include_reasoning` properties.
- Updated tests to ensure that `reasoning_summary` is excluded from the reasoning object and that the configuration behaves correctly based on the presence of reasoning parameters.
- Enhanced test coverage for OpenRouter-specific configurations, ensuring proper handling of various reasoning effort levels.

* refactor: Improve OpenRouter reasoning handling in LLM configuration

- Updated the handling of the `reasoning` object in the OpenRouter configuration to clarify the relationship between `reasoning_effort` and `include_reasoning`.
- Enhanced comments to explain the behavior of the `reasoning` object and its compatibility with legacy parameters.
- Ensured that the configuration correctly falls back to legacy behavior when no explicit reasoning effort is provided.

* test: Enhance OpenRouter LLM configuration tests

- Added a new test to verify the combination of web search plugins and reasoning object for OpenRouter configurations.
- Updated existing tests to ensure proper handling of reasoning effort levels and fallback behavior when reasoning_effort is unset.
- Improved test coverage for OpenRouter-specific configurations, ensuring accurate validation of reasoning parameters.

* chore: Update @librechat/agents dependency to version 3.1.53

- Bumped the version of @librechat/agents in package-lock.json and related package.json files to ensure compatibility with the latest features and fixes.
- Updated integrity hashes to reflect the new version.

api/package.json

@@ -44,7 +44,7 @@
     "@google/genai": "^1.19.0",
     "@keyv/redis": "^4.3.3",
     "@langchain/core": "^0.3.80",
-    "@librechat/agents": "^3.1.52",
+    "@librechat/agents": "^3.1.53",
     "@librechat/api": "*",
     "@librechat/data-schemas": "*",
     "@microsoft/microsoft-graph-client": "^3.0.7",