🔒 feat: Add MCP server domain restrictions for remote transports (#11013)

* 🔒 feat: Add MCP server domain restrictions for remote transports

* 🔒 feat: Implement comprehensive MCP error handling and domain validation

- Added `handleMCPError` function to centralize error responses for domain restrictions and inspection failures.
- Introduced custom error classes: `MCPDomainNotAllowedError` and `MCPInspectionFailedError` for better error management.
- Updated MCP server controllers to utilize the new error handling mechanism.
- Enhanced domain validation logic in `createMCPTools` and `createMCPTool` functions to prevent operations on disallowed domains.
- Added tests for runtime domain validation scenarios to ensure correct behavior.

* chore: import order

* 🔒 feat: Enhance domain validation in MCP tools with user role-based restrictions

- Integrated `getAppConfig` to fetch allowed domains based on user roles in `createMCPTools` and `createMCPTool` functions.
- Removed the deprecated `getAllowedDomains` method from `MCPServersRegistry`.
- Updated tests to verify domain restrictions are applied correctly based on user roles.
- Ensured that domain validation logic is consistent and efficient across tool creation processes.

* 🔒 test: Refactor MCP tests to utilize configurable app settings

- Introduced a mock for `getAppConfig` to enhance test flexibility.
- Removed redundant mock definition to streamline test setup.
- Ensured tests are aligned with the latest domain validation logic.

---------

Co-authored-by: Atef Bellaaj <slalom.bellaaj@external.daimlertruck.com>
Co-authored-by: Danny Avila <danny@librechat.ai>

client/src/components/SidePanel/MCPBuilder/MCPServerDialog.tsx

@@ -308,6 +308,8 @@ export default function MCPServerDialog({
         const axiosError = error as any;
         if (axiosError.response?.data?.error === 'MCP_INSPECTION_FAILED') {
           errorMessage = localize('com_ui_mcp_server_connection_failed');
+        } else if (axiosError.response?.data?.error === 'MCP_DOMAIN_NOT_ALLOWED') {
+          errorMessage = localize('com_ui_mcp_domain_not_allowed');
         } else if (axiosError.response?.data?.error) {
           errorMessage = axiosError.response.data.error;
         }