docs: update plans based on Codex review

Codex review findings applied:
- Use CTE pattern to pre-filter valid JSON before OPENJSON
- Use OPENJSON...WITH for type-safe extraction (avoids double TRY_CONVERT)
- Keep script gaps instead of renumbering (prevents migration drift)
- Add xUnit Collection for test isolation (prevents parallel execution issues)

PLANS/2026-01-06-search-criteria-extraction-design.md

@@ -309,39 +309,38 @@ Share with `Api.IntegrationTests` via `TestWebApplicationFactory` pattern.
 
 ### Phase 1: SQL Functions & Procedure
 1. Create `045_CreateScalarExtractionFunctions.sql` (3 scalar functions)
-2. Create `046_CreateSimpleTableFunctions.sql` (5 inline TVFs)
+2. Create `046_CreateSimpleTableFunctions.sql` (5 inline TVFs with CTE pattern)
 3. Create `047_CreateComplexTableFunctions.sql` (2 inline TVFs with OPENJSON...WITH)
 4. Create `048_CreateValidateSearchCriteriaProcedure.sql` (validation procedure)
-5. Delete obsolete Table Type scripts (033-039)
-6. Renumber remaining scripts (040-044 → 033-037)
+5. Delete obsolete Table Type scripts (033-039) - keep gaps, don't renumber
 
 ### Phase 2: Database Tests
-7. Set up `DatabaseTestBase.cs`
-8. Write `ScalarFunctionTests.cs`
-9. Write `SimpleTableFunctionTests.cs`
-10. Write `ComplexTableFunctionTests.cs`
-11. Write `ValidateSearchCriteriaProcedureTests.cs`
-12. Verify all tests pass
+6. Set up `DatabaseTestBase.cs` with xUnit Collection for isolation
+7. Write `ScalarFunctionTests.cs`
+8. Write `SimpleTableFunctionTests.cs`
+9. Write `ComplexTableFunctionTests.cs`
+10. Write `ValidateSearchCriteriaProcedureTests.cs`
+11. Verify all tests pass
 
 ### Phase 3: C# Refactor
-13. Update `ISearchQueryBuilder` interface
-14. Update `SqlKataSearchQueryBuilder`
-15. Update `SearchProcessor`
-16. Simplify `SearchModel`
-17. Delete `TableValuedParameterExtensions.cs`
-18. Delete `FilterEntries/*.cs`
-19. Update/delete related tests
+12. Update `ISearchQueryBuilder` interface
+13. Update `SqlKataSearchQueryBuilder`
+14. Update `SearchProcessor`
+15. Simplify `SearchModel`
+16. Delete `TableValuedParameterExtensions.cs`
+17. Delete `FilterEntries/*.cs`
+18. Update/delete related tests
 
 ### Phase 4: Integration & Verification
-20. Run full test suite
-21. Fix broken tests
-22. Manual end-to-end verification
+19. Run full test suite
+20. Fix broken tests
+21. Manual end-to-end verification
 
 ### Phase 5: Documentation
-23. Update OpenSpec specifications
-24. Update architecture documentation
-25. Add Database.Tests documentation
-26. Create ExtractionFunctions.md reference
+22. Update OpenSpec specifications
+23. Update architecture documentation
+24. Add Database.Tests documentation
+25. Create ExtractionFunctions.md reference
 
 ## Acceptance Criteria