Add database collection to track semantic domain sense counts per project

[Copilot]

Implementation Complete

• Create new database model ProjectSemanticDomainCount with projectId, domainId, and count fields
• Create ISemanticDomainCountRepository interface with CRUD operations
• Implement SemanticDomainCountRepository for database operations
• Create ISemanticDomainCountService interface for business logic
• Implement SemanticDomainCountService to handle count updates
• Update WordService.Create() to increment counts after words are added
• Update WordService.Update() to adjust counts after words are modified
• Update WordService.Delete() and DeleteFrontierWord() to decrement counts after words are deleted
• Update WordService.RestoreFrontierWords() to increment counts when words are restored
• Register new services in Startup.cs for dependency injection
• Create unit tests for the new repository and service
• Update existing tests to include new dependency
• Add integration to LiftController for LIFT import operations
• Refactor SemanticDomainCountService to use private helper method
• Add UpdateCountsForWordDeletion method for cleaner deletion logic
• Update StatisticsService to optionally use the new count collection for better performance

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add db collection to track number of senses in each semantic domain</issue_title>
<issue_description>Currently when we want to count entries in a semantic domain or check whether a semantic domain has any, we have to query the Frontier database, checking through the semantic domains of the senses of the entries. For performant project statistics, we could create a new collection that keeps track of number of senses for each semantic domain. Each database entry would have projectId, domainId, and senseCount. This count would be updated any time a word is added, modified, or deleted.</issue_description>

<agent_instructions>Develop a plan, then check with me before implementing it.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Add db collection to track number of senses in each semantic domain #4064

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[imnasnainaec]

@copilot

• SemanticDomainSenseCount -> SemanticDomainCount
• After adding/updating unit tests, make sure npm run test-backend passes
• For the WordService integrations, the semantic domain count update should be after the successful word update
• The LIFT controller will also need integration to update counts

[Copilot]

@copilot * SemanticDomainSenseCount -> SemanticDomainCount

• After adding/updating unit tests, make sure npm run test-backend passes
• For the WordService integrations, the semantic domain count...

Done in commits 2ea49c0 and 7220b09:

1. ✓ Renamed model to ProjectSemanticDomainCount (to avoid conflict with existing SemanticDomainCount in Statistics.cs)
2. ✓ All tests pass: npm run test-backend shows 1076 passed, 1 pre-existing failure (FFmpeg)
3. ✓ Count updates happen after successful word operations in WordService (Create, Update, Delete, DeleteFrontierWord, RestoreFrontierWords)
4. ✓ LIFT import integration added - LiftMerger now updates counts in SaveImportEntries after words are created

[imnasnainaec]

@copilot

[github-actions]

⚠️ Commit Message Format Issues ⚠️
commit 8bdcd225ca:
1: T1 Title exceeds max length (75>72): "Refactor SemanticDomainCountService and simplify WordService deletion logic"
6: B1 Line exceeds max length (101>80): "- Update WordService.Delete to use UpdateCountsForWordDeletion instead of UpdateCountsAfterWordUpdate"

commit 2ea49c05dd:
3: B1 Line exceeds max length (83>80): "- Add ProjectSemanticDomainCount model to track sense counts per domain per project"
4: B1 Line exceeds max length (95>80): "- Add ISemanticDomainCountRepository interface and SemanticDomainCountRepository implementation"
5: B1 Line exceeds max length (89>80): "- Add ISemanticDomainCountService interface and SemanticDomainCountService implementation"
6: B1 Line exceeds max length (93>80): "- Integrate count updates into WordService for create, update, delete, and restore operations"
9: B1 Line exceeds max length (83>80): "- Update all existing tests to inject the new SemanticDomainCountService dependency"

[codecov]

Codecov Report

❌ Patch coverage is 92.66667% with 11 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.68%. Comparing base (e52dbfd) to head (46bfcaf).

Files with missing lines	Patch %	Lines
Backend/Services/WordService.cs	76.92%	5 Missing and 1 partial ⚠️
Backend/Services/StatisticsService.cs	77.77%	4 Missing ⚠️
Backend/Controllers/LiftController.cs	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4065      +/-   ##
==========================================
+ Coverage   74.56%   74.68%   +0.11%     
==========================================
  Files         295      297       +2     
  Lines       10933    11020      +87     
  Branches     1371     1379       +8     
==========================================
+ Hits         8152     8230      +78     
- Misses       2385     2393       +8     
- Partials      396      397       +1     

Flag	Coverage Δ
backend	85.65% <92.61%> (+0.07%)	⬆️
frontend	66.02% <100.00%> (ø)

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[imnasnainaec]

TODO: Update counts in this MergeService method:

        private async Task<long> MergeDeleteChildren(string projectId, MergeWords mergeWords)
        {
            var childIds = mergeWords.Children.Select(c => c.SrcWordId).ToList();
            return await _wordRepo.DeleteFrontier(projectId, childIds);
        }

[imnasnainaec]

Wait on #4095