[SSR Agent] Issue Fix (283): Update LLMResponse usageMetadata documentation

[joneba-google]

fixes #283
Original issue: #283

Context & Problem

The hook reference documentation for LLMResponse.usageMetadata incorrectly omitted promptTokenCount and candidatesTokenCount. This was due to incomplete documentation in docs/hooks/reference.md relative to the exported LLMResponse interface and the hook translator implementation in packages/core/src/hooks/hookTranslator.ts.

Detailed Changes

• docs/hooks/reference.md: Updated the usageMetadata schema block under LLMResponse to explicitly document promptTokenCount, candidatesTokenCount, and totalTokenCount.
• packages/core/src/hooks/hookTranslator.test.ts: Added a unit test to verify that converting hook responses back to the SDK format correctly preserves usageMetadata token counts (promptTokenCount, candidatesTokenCount, and totalTokenCount).

Verification

• Static inspection verifies that the documented properties align perfectly with the LLMResponse TypeScript interface.
• Unit tests in packages/core/src/hooks/hookTranslator.test.ts have been added to prevent regressions.
• The linter check run on the modified files completed successfully with no errors or warnings.

[github-actions]

📊 PR Size: size/S

• Lines changed: 34
• Additions: +33
• Deletions: -1
• Files changed: 2