🎭 feat: Override Custom Endpoint Schema with Specified Params Endpoint (#11788)

* 🔧 refactor: Simplify payload parsing and enhance getSaveOptions logic

- Removed unused bedrockInputSchema from payloadParser, streamlining the function.
- Updated payloadParser to handle optional chaining for model parameters.
- Enhanced getSaveOptions to ensure runOptions defaults to an empty object if parsing fails, improving robustness.
- Adjusted the assignment of maxContextTokens to use the instance variable for consistency.

* 🔧 fix: Update maxContextTokens assignment logic in initializeAgent function

- Enhanced the maxContextTokens assignment to allow for user-defined values, ensuring it defaults to a calculated value only when not provided or invalid. This change improves flexibility in agent initialization.

* 🧪 test: Add unit tests for initializeAgent function

- Introduced comprehensive unit tests for the initializeAgent function, focusing on maxContextTokens behavior.
- Tests cover scenarios for user-defined values, fallback calculations, and edge cases such as zero and negative values, enhancing overall test coverage and reliability of agent initialization logic.

* refactor: default params Endpoint Configuration Handling

- Integrated `getEndpointsConfig` to fetch endpoint configurations, allowing for dynamic handling of `defaultParamsEndpoint`.
- Updated `buildEndpointOption` to pass `defaultParamsEndpoint` to `parseCompactConvo`, ensuring correct parameter handling based on endpoint type.
- Added comprehensive unit tests for `buildDefaultConvo` and `cleanupPreset` to validate behavior with `defaultParamsEndpoint`, covering various scenarios and edge cases.
- Refactored related hooks and utility functions to support the new configuration structure, improving overall flexibility and maintainability.

* refactor: Centralize defaultParamsEndpoint retrieval

- Introduced `getDefaultParamsEndpoint` function to streamline the retrieval of `defaultParamsEndpoint` across various hooks and middleware.
- Updated multiple files to utilize the new function, enhancing code consistency and maintainability.
- Removed redundant logic for fetching `defaultParamsEndpoint`, simplifying the codebase.

packages/data-provider/src/config.ts

@@ -1908,3 +1908,14 @@ export function getEndpointField<
   }
   return config[property];
 }
+
+/** Resolves the `defaultParamsEndpoint` for a given endpoint from its custom params config */
+export function getDefaultParamsEndpoint(
+  endpointsConfig: TEndpointsConfig | undefined | null,
+  endpoint: string | null | undefined,
+): string | undefined {
+  if (!endpointsConfig || !endpoint) {
+    return undefined;
+  }
+  return endpointsConfig[endpoint]?.customParams?.defaultParamsEndpoint;
+}