test(providers): cover Gemini speech support and HuggingFace error handling gaps

[aaight]

Summary

Adds unit tests to close coverage gaps in the Gemini and HuggingFace provider adapters.

• Gemini (gemini.test.ts): tests for supportsSpeechGeneration (lines 360-362) and buildApiRequest (lines 429-442)
• HuggingFace (huggingface.test.ts): tests for DeepSeek reasoning injection (lines 67-72) and enhanceError with non-Error values (lines 82-83)

Closes https://linear.app/mongrel/issue/MNG-266

Changes

• packages/llmist/src/providers/gemini.test.ts: Added describe("supportsSpeechGeneration") block (returns true for known TTS models, false for others) and describe("buildApiRequest") block (message conversion, option passthrough, content verification)
• packages/llmist/src/providers/huggingface.test.ts: Added 3 tests for DeepSeek thinking-mode injection (enabled, disabled, non-DeepSeek) and 1 test for enhanceError with non-Error input types

Test plan

• npm run test passes — all 6537 tests pass (219 test files)
• npx biome check on changed files — no errors (only pre-existing any warnings consistent with rest of test suite)
• No production code changes — test-only PR

🕵️ claude-code · claude-sonnet-4-6 · run details

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[nhopeatall]

LGTM - Tests correctly exercise the targeted coverage gaps: Gemini supportsSpeechGeneration dispatches to isGeminiSpeechModel, buildApiRequest message conversion and option passthrough, HuggingFace DeepSeek thinking-mode injection logic, and enhanceError non-Error coercion path. All assertions align with the actual implementation. CI green.

🕵️ claude-code · claude-opus-4-6 · run details

[nhopeatall]

LGTM - Clean test-only PR that correctly covers the targeted gaps: Gemini supportsSpeechGeneration delegation, buildApiRequest message conversion/option passthrough, HuggingFace DeepSeek thinking-mode injection (enabled, disabled, non-DeepSeek), and enhanceError non-Error coercion. All assertions verified against the source implementations. CI green.

🕵️ claude-code · claude-opus-4-6 · run details