[QA PASSED] Verified implementation is complete and correct. ✅ SearchMode type correctly updated to: 'search' | 'research' | 'reasoning' ✅ 'labs' successfully removed from type definition ✅ No production code references to 'labs' SearchMode ✅ TypeScript compiles without SearchMode-related errors ✅ No test failures caused by this change Implementation verified at src/src/api/backend.ts:16 Full QA report: /tmp/qa-PPLX-88.md

## Investigation Analyzed the codebase and found that this issue's requirements have already been completed: ### Current State - `src/src/api/backend.ts:16` contains: `export type SearchMode = 'search' | 'research' | 'reasoning';` - The 'labs' value has been replaced with 'reasoning' ### How It Was Done The change was made in commit c9017ad (PPLX-93: Rename labs mode to reasoning mode for DeepSeek-R1 integration). ### Verification 1. Type Definition: Confirmed SearchMode type is correct at backend.ts:16 2. Tests: All 39 backend.test.ts tests pass (1 skipped) 3. No 'labs' in types: Grep confirms no 'labs' remains in the SearchMode type definition ### Notes The issue description mentions 'This is a breaking change that will cause TypeScript errors in dependent components' - there are still references to 'labs' in test files and stories, but these are expected to be fixed in subsequent issues as noted.