fix(gateway): guard non-array tools in api metrics

[kirillk]

Summary

• guard API metrics tool extraction against truthy non-array tools payloads so /api/gateway/chat/completions does not throw before reaching the upstream provider
• add regression coverage for object-shaped tools payloads while preserving existing array-based extraction behavior
• keep the fix scoped to observability preprocessing, matching the incident where the crash happened in getToolsAvailable

Validation

• pnpm lint src/lib/o11y/api-metrics.server.ts src/lib/o11y/api-metrics.server.test.ts
• pnpm test -- --runInBand src/lib/o11y/api-metrics.server.test.ts

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (2 files)

• src/lib/o11y/api-metrics.server.ts
• src/lib/o11y/api-metrics.server.test.ts

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_{Reviewed by gpt-5.4-20260305 · 152,082 tokens}