feat(cv-matcher): add AiPrompts table; remove MyAiDbContext dependency

cv-matcher-data:
- Add AiPromptEntity (Key, Language, Value, Description, UpdatedAt)
- Add AiPrompts DbSet to CvMatcherDbContext with composite PK
- Migration AddAiPrompts: create cvMatcher.AiPrompts table and seed
  ai.cv-match.system-prompt (language "*") with the current prompt value

cv-matcher-api:
- Add IAiPromptsRepository / EfAiPromptsRepository under Data/Repositories/
- CvMatcherService: inject IAiPromptsRepository; replace _templates.Render(...)
  with async DB lookup + simple string replacement
- Program.cs: register IAiPromptsRepository (scoped); remove MyAiDbContext,
  ITemplateService/DbTemplateService registrations and MyAiDbContext migration call
- Remove myai-data ProjectReference

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Apis/cv-matcher-api/Services/CvMatcherService.cs

@@ -7,7 +7,6 @@ using CvMatcher.Models.Responses;
 using CvMatcher.Models.Settings;
 using Api.Services.Contracts;
 using Microsoft.Extensions.Options;
-using MyAi.Data.Services;
 
 namespace Api.Services;
 
@@ -17,23 +16,23 @@ public sealed class CvMatcherService : ICvMatcherService
     private readonly IJobTextExtractor _jobTextExtractor;
     private readonly IMatcherAiClient _ai;
     private readonly IMatcherRepository _repository;
+    private readonly IAiPromptsRepository _aiPrompts;
     private readonly MatcherSettings _settings;
-    private readonly ITemplateService _templates;
 
     public CvMatcherService(
         IRagApiClient rag,
         IJobTextExtractor jobTextExtractor,
         IMatcherAiClient ai,
         IMatcherRepository repository,
-        IOptions<MatcherSettings> options,
-        ITemplateService templates)
+        IAiPromptsRepository aiPrompts,
+        IOptions<MatcherSettings> options)
     {
         _rag = rag;
         _jobTextExtractor = jobTextExtractor;
         _ai = ai;
         _repository = repository;
+        _aiPrompts = aiPrompts;
         _settings = options.Value;
-        _templates = templates;
     }
 
     public async Task<CvUploadResponse> UploadCvAsync(IFormFile file, CancellationToken ct)
@@ -115,8 +114,9 @@ public sealed class CvMatcherService : ICvMatcherService
         var evidence = evidenceChunks.Count > 0 ? string.Join("\n\n", evidenceChunks.Take(4)) : Limit(job.Text, 4000);
         var languageName = LanguageName(language);
 
-        var systemPrompt = _templates.Render("ai.cv-match.system-prompt", "*",
-            ("languageName", languageName));
+        var promptTemplate = await _aiPrompts.GetAsync("ai.cv-match.system-prompt", "*", ct)
+            ?? "You are a strict CV-to-job matching engine. Return JSON only.";
+        var systemPrompt = promptTemplate.Replace("{{languageName}}", languageName, StringComparison.OrdinalIgnoreCase);
 
         var userPrompt = $"""
             CV: