* fix: Convert `const` to `enum` in MCP tool schemas for Gemini/Vertex AI compatibility
Gemini/Vertex AI rejects the JSON Schema `const` keyword in function declarations
with a 400 error. Previously, the Zod conversion layer accidentally stripped `const`,
but after migrating to pass raw JSON schemas directly to providers, the unsupported
keyword now reaches Gemini verbatim.
Add `normalizeJsonSchema` to recursively convert `const: X` → `enum: [X]`, which is
semantically equivalent per the JSON Schema spec and supported by all providers.
* fix: Update secure cookie handling in AuthService to use dynamic secure flag
Replaced the static `secure: isProduction` with a call to `shouldUseSecureCookie()` in the `setOpenIDAuthTokens` function. This change ensures that the secure cookie setting is evaluated at runtime, improving cookie handling in development environments while maintaining security in production.
* refactor: Simplify MCP tool key formatting and remove unused mocks in tests
- Updated MCP test suite to replace static tool key formatting with a dynamic delimiter from Constants, enhancing consistency and maintainability.
- Removed unused mock implementations for `@langchain/core/tools` and `@librechat/agents`, streamlining the test setup.
- Adjusted related test cases to reflect the new tool key format, ensuring all tests remain functional.
* chore: import order
ccbf9dc093