Update UNIFIED_SEARCH_IMPLEMENTATION.md with:
1. Technical note about sqlc v1.30.0 limitation:
- CASE expressions in GROUP BY not supported
- Solution: Use 4 separate simple queries instead of 1 complex query
- Simpler approach that works correctly with current sqlc version
2. Implementation approach updates:
- Service layer route to appropriate query based on field type
- No changes needed to main.go or test helpers
- SearchService created inside handler constructor
3. Phase 7 changes (skip):
- No handler initialization changes needed
- Follows FiltersService and CollectionService pattern
- Rationale: more testable, simpler initialization
4. Updated timeline estimates
5. Updated success criteria
These notes clarify implementation decisions and provide context
for future maintainers.