- Added `clientDeclaredTools` to `xaiInternalXSearchResponseFilter` for improved filtering precision.
- Implemented `collectXAIClientDeclaredToolKeys` to register client-declared tools with effective normalization to function calls.
- Prevented leakage of internal traces (e.g., `xs_call-*`) while preserving client-declared tools with overlapping names.
- Introduced multiple test cases to ensure filter correctness and preserve expected WebSocket response outputs.
- Enhanced completed output handling in response filtering.
Closes: #4282 / PR #4284.