#21471: fix: check QMD backend before memory search config

Fixes #21443 ## Summary When `memory.backend` is set to `qmd`, `openclaw doctor` was still showing the embedding-provider warning, despite QMD managing embeddings internally. ## Root Cause The QMD backend check was implemented (#17263) but ran **after** memory search config resolution, which could cause it to be skipped in certain configuration states. ## Changes - Moved QMD backend check to the top of `noteMemorySearchHealth()` - Now checks QMD backend **before** resolving memory search config - Added clarifying comment explaining the check order ## Testing - All existing tests pass (`doctor-memory-search.test.ts`) - QMD backend check now runs first, ensuring no false warnings ## Closes #21443 <!-- greptile_comment --> <h3>Greptile Summary</h3> Reordered QMD backend check to run before memory search config resolution, preventing false embedding-provider warnings when using QMD. QMD handles embeddings internally and doesn't require a separate provider, so the check correctly exits early before any provider validation logic runs. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk - Simple reordering fix with existing test coverage confirming QMD backend check behavior. The change is minimal (moving 6 lines earlier), logic is unchanged, and all tests pass. The fix addresses a clear bug where QMD users received false warnings. - No files require special attention _{Last reviewed commit: 05c5205} <!-- greptile_other_comments_section --> _{(4/5) You can add custom instructions or style guidelines for the agent [here](https://app.greptile.com/review/github)!} <!-- /greptile_comment -->