feat(backend): Add AuditLog repository interface and implementation

Implement repository pattern for AuditLog entity for Sprint 2 Story 1 Task 2.

Changes:
- Created IAuditLogRepository interface with 6 query methods
- Implemented AuditLogRepository with efficient querying
- Registered repository in DI container
- All queries use AsNoTracking for read-only operations

Query Methods:
- GetByIdAsync: Get single audit log by ID
- GetByEntityAsync: Get audit history for specific entity
- GetByUserAsync: Get user activity with pagination
- GetRecentAsync: Get recent audit logs
- AddAsync: Add new audit log
- GetCountAsync: Get total audit log count

Performance:
- All queries automatically filtered by TenantId (Global Query Filter)
- Efficient use of composite indexes
- AsNoTracking for read-only operations

Testing:
- All tests passing (192 domain + 113 identity + 8 arch + 32 app + 12 infra = 357 tests)
- No compilation errors
- Zero test failures

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

colaflow-api/src/ColaFlow.API/Extensions/ModuleExtensions.cs

@@ -45,6 +45,7 @@ public static class ModuleExtensions
 
         // Register repositories
         services.AddScoped<IProjectRepository, ProjectRepository>();
+        services.AddScoped<IAuditLogRepository, ColaFlow.Modules.ProjectManagement.Infrastructure.Repositories.AuditLogRepository>();
         services.AddScoped<IUnitOfWork, ColaFlow.Modules.ProjectManagement.Infrastructure.Persistence.UnitOfWork>();
 
         // Register services

colaflow-api/src/Modules/ProjectManagement/ColaFlow.Modules.ProjectManagement.Domain/Repositories/IAuditLogRepository.cs

@@ -0,0 +1,27 @@
+using ColaFlow.Modules.ProjectManagement.Domain.Entities;
+
+namespace ColaFlow.Modules.ProjectManagement.Domain.Repositories;
+
+public interface IAuditLogRepository
+{
+    Task<AuditLog?> GetByIdAsync(Guid id, CancellationToken cancellationToken = default);
+
+    Task<IReadOnlyList<AuditLog>> GetByEntityAsync(
+        string entityType,
+        Guid entityId,
+        CancellationToken cancellationToken = default);
+
+    Task<IReadOnlyList<AuditLog>> GetByUserAsync(
+        Guid userId,
+        int pageNumber = 1,
+        int pageSize = 50,
+        CancellationToken cancellationToken = default);
+
+    Task<IReadOnlyList<AuditLog>> GetRecentAsync(
+        int count = 100,
+        CancellationToken cancellationToken = default);
+
+    Task AddAsync(AuditLog auditLog, CancellationToken cancellationToken = default);
+
+    Task<int> GetCountAsync(CancellationToken cancellationToken = default);
+}

colaflow-api/src/Modules/ProjectManagement/ColaFlow.Modules.ProjectManagement.Infrastructure/Repositories/AuditLogRepository.cs

@@ -0,0 +1,72 @@
+using ColaFlow.Modules.ProjectManagement.Domain.Entities;
+using ColaFlow.Modules.ProjectManagement.Domain.Repositories;
+using ColaFlow.Modules.ProjectManagement.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace ColaFlow.Modules.ProjectManagement.Infrastructure.Repositories;
+
+public class AuditLogRepository : IAuditLogRepository
+{
+    private readonly PMDbContext _context;
+
+    public AuditLogRepository(PMDbContext context)
+    {
+        _context = context;
+    }
+
+    public async Task<AuditLog?> GetByIdAsync(Guid id, CancellationToken cancellationToken = default)
+    {
+        return await _context.AuditLogs
+            .AsNoTracking()
+            .FirstOrDefaultAsync(a => a.Id == id, cancellationToken);
+    }
+
+    public async Task<IReadOnlyList<AuditLog>> GetByEntityAsync(
+        string entityType,
+        Guid entityId,
+        CancellationToken cancellationToken = default)
+    {
+        return await _context.AuditLogs
+            .AsNoTracking()
+            .Where(a => a.EntityType == entityType && a.EntityId == entityId)
+            .OrderByDescending(a => a.Timestamp)
+            .ToListAsync(cancellationToken);
+    }
+
+    public async Task<IReadOnlyList<AuditLog>> GetByUserAsync(
+        Guid userId,
+        int pageNumber = 1,
+        int pageSize = 50,
+        CancellationToken cancellationToken = default)
+    {
+        return await _context.AuditLogs
+            .AsNoTracking()
+            .Where(a => a.UserId == userId)
+            .OrderByDescending(a => a.Timestamp)
+            .Skip((pageNumber - 1) * pageSize)
+            .Take(pageSize)
+            .ToListAsync(cancellationToken);
+    }
+
+    public async Task<IReadOnlyList<AuditLog>> GetRecentAsync(
+        int count = 100,
+        CancellationToken cancellationToken = default)
+    {
+        return await _context.AuditLogs
+            .AsNoTracking()
+            .OrderByDescending(a => a.Timestamp)
+            .Take(count)
+            .ToListAsync(cancellationToken);
+    }
+
+    public async Task AddAsync(AuditLog auditLog, CancellationToken cancellationToken = default)
+    {
+        await _context.AuditLogs.AddAsync(auditLog, cancellationToken);
+        await _context.SaveChangesAsync(cancellationToken);
+    }
+
+    public async Task<int> GetCountAsync(CancellationToken cancellationToken = default)
+    {
+        return await _context.AuditLogs.CountAsync(cancellationToken);
+    }
+}

docs/plans/sprint_2_story_1_task_2.md

@@ -1,9 +1,10 @@
 ---
 task_id: sprint_2_story_1_task_2
 story: sprint_2_story_1
-status: not_started
+status: in_progress
 estimated_hours: 4
 created_date: 2025-11-05
+start_date: 2025-11-05
 assignee: Backend Team
 ---