Refactor nunit tests off InMemory/WebApplicationFactory, remove tuple returns (#4)

## Summary
- Extract `IMicCheckDbContext` and mock DB access with Moq instead of the EF InMemory provider, per CLAUDE.md testing guidelines.
- Rewrite HTTP-pipeline tests to exercise controllers/auth handlers directly instead of `WebApplicationFactory`.
- Remove tuple return types across the API in favor of named records (`PagedResult<T>`, `ProfileUpdateResult`, `ApiKeyCreationResult`).

## Test plan
- [x] `dotnet build` (full solution)
- [x] `dotnet test tests/api/MicCheck.Api.Tests.Unit` — 187/187 pass
- [x] `dotnet test tests/api/MicCheck.Api.Tests.Integration` — 8/8 pass (live API + Postgres via Aspire)
- [x] Verified Aspire AppHost/dashboard starts and API responds

Reviewed-on: #4

src/api/MicCheck.Api/Audit/AuditLogQueryService.cs

@@ -1,32 +1,33 @@
+using MicCheck.Api.Common;
 using MicCheck.Api.Data;
 using Microsoft.EntityFrameworkCore;
 
 namespace MicCheck.Api.Audit;
 
-public class AuditLogQueryService(MicCheckDbContext db)
+public class AuditLogQueryService(IMicCheckDbContext db)
 {
-    public async Task<(int Total, IReadOnlyList<AuditLogResponse> Items)> ListByOrganizationAsync(
+    public async Task<PagedResult<AuditLogResponse>> ListByOrganizationAsync(
         int organizationId, AuditLogFilter filter, CancellationToken ct = default)
     {
         var query = db.AuditLogs.Where(l => l.OrganizationId == organizationId);
         return await ApplyFilterAndPageAsync(query, filter, ct);
     }
 
-    public async Task<(int Total, IReadOnlyList<AuditLogResponse> Items)> ListByProjectAsync(
+    public async Task<PagedResult<AuditLogResponse>> ListByProjectAsync(
         int projectId, AuditLogFilter filter, CancellationToken ct = default)
     {
         var query = db.AuditLogs.Where(l => l.ProjectId == projectId);
         return await ApplyFilterAndPageAsync(query, filter, ct);
     }
 
-    public async Task<(int Total, IReadOnlyList<AuditLogResponse> Items)> ListByEnvironmentAsync(
+    public async Task<PagedResult<AuditLogResponse>> ListByEnvironmentAsync(
         int environmentId, AuditLogFilter filter, CancellationToken ct = default)
     {
         var query = db.AuditLogs.Where(l => l.EnvironmentId == environmentId);
         return await ApplyFilterAndPageAsync(query, filter, ct);
     }
 
-    private async Task<(int Total, IReadOnlyList<AuditLogResponse> Items)> ApplyFilterAndPageAsync(
+    private async Task<PagedResult<AuditLogResponse>> ApplyFilterAndPageAsync(
         IQueryable<AuditLog> query, AuditLogFilter filter, CancellationToken ct)
     {
         if (filter.From.HasValue)
@@ -63,6 +64,6 @@ public class AuditLogQueryService(MicCheckDbContext db)
                     user != null ? user.FirstName + " " + user.LastName : null))
             .ToListAsync(ct);
 
-        return (total, items);
+        return new PagedResult<AuditLogResponse>(total, items);
     }
 }

src/api/MicCheck.Api/Audit/AuditLogsController.cs

@@ -1,59 +1,59 @@
-using MicCheck.Api.Common.Security.Authorization;
-using MicCheck.Api.Common;
-using MicCheck.Api.Environments;
-using MicCheck.Api.Projects;
-using MicCheck.Api.Organizations;
-using Microsoft.AspNetCore.Authorization;
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.RateLimiting;
-
-namespace MicCheck.Api.Audit;
-
-[ApiController]
-[Authorize(Policy = AuthorizationPolicies.AdminApiAccess)]
-[EnableRateLimiting("AdminApi")]
-public class AuditLogsController(
-    AuditLogQueryService auditLogQueryService,
-    OrganizationService organizationService,
-    ProjectService projectService,
-    EnvironmentService environmentService) : ControllerBase
-{
-    [HttpGet("api/v1/organisation/{id}/audit-logs")]
-    public async Task<ActionResult<PaginatedResponse<AuditLogResponse>>> ListByOrganization(
-        int id,
-        [FromQuery] AuditLogFilter filter,
-        CancellationToken ct)
-    {
-        var org = await organizationService.FindByIdAsync(id, ct);
-        if (org is null) return NotFound();
-
-        var (total, logs) = await auditLogQueryService.ListByOrganizationAsync(id, filter, ct);
-        return Ok(new PaginatedResponse<AuditLogResponse>(total, null, null, logs.ToList()));
-    }
-
-    [HttpGet("api/v1/project/{projectId}/audit-logs")]
-    public async Task<ActionResult<PaginatedResponse<AuditLogResponse>>> ListByProject(
-        int projectId,
-        [FromQuery] AuditLogFilter filter,
-        CancellationToken ct)
-    {
-        var project = await projectService.FindByIdAsync(projectId, ct);
-        if (project is null) return NotFound();
-
-        var (total, logs) = await auditLogQueryService.ListByProjectAsync(projectId, filter, ct);
-        return Ok(new PaginatedResponse<AuditLogResponse>(total, null, null, logs.ToList()));
-    }
-
-    [HttpGet("api/v1/environment/{apiKey}/audit-logs")]
-    public async Task<ActionResult<PaginatedResponse<AuditLogResponse>>> ListByEnvironment(
-        string apiKey,
-        [FromQuery] AuditLogFilter filter,
-        CancellationToken ct)
-    {
-        var environment = await environmentService.FindByApiKeyAsync(apiKey, ct);
-        if (environment is null) return NotFound();
-
-        var (total, logs) = await auditLogQueryService.ListByEnvironmentAsync(environment.Id, filter, ct);
-        return Ok(new PaginatedResponse<AuditLogResponse>(total, null, null, logs.ToList()));
-    }
-}
+using MicCheck.Api.Common.Security.Authorization;
+using MicCheck.Api.Common;
+using MicCheck.Api.Environments;
+using MicCheck.Api.Projects;
+using MicCheck.Api.Organizations;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.RateLimiting;
+
+namespace MicCheck.Api.Audit;
+
+[ApiController]
+[Authorize(Policy = AuthorizationPolicies.AdminApiAccess)]
+[EnableRateLimiting("AdminApi")]
+public class AuditLogsController(
+    AuditLogQueryService auditLogQueryService,
+    OrganizationService organizationService,
+    ProjectService projectService,
+    EnvironmentService environmentService) : ControllerBase
+{
+    [HttpGet("api/v1/organisation/{id}/audit-logs")]
+    public async Task<ActionResult<PaginatedResponse<AuditLogResponse>>> ListByOrganization(
+        int id,
+        [FromQuery] AuditLogFilter filter,
+        CancellationToken ct)
+    {
+        var org = await organizationService.FindByIdAsync(id, ct);
+        if (org is null) return NotFound();
+
+        var result = await auditLogQueryService.ListByOrganizationAsync(id, filter, ct);
+        return Ok(new PaginatedResponse<AuditLogResponse>(result.Total, null, null, result.Items.ToList()));
+    }
+
+    [HttpGet("api/v1/project/{projectId}/audit-logs")]
+    public async Task<ActionResult<PaginatedResponse<AuditLogResponse>>> ListByProject(
+        int projectId,
+        [FromQuery] AuditLogFilter filter,
+        CancellationToken ct)
+    {
+        var project = await projectService.FindByIdAsync(projectId, ct);
+        if (project is null) return NotFound();
+
+        var result = await auditLogQueryService.ListByProjectAsync(projectId, filter, ct);
+        return Ok(new PaginatedResponse<AuditLogResponse>(result.Total, null, null, result.Items.ToList()));
+    }
+
+    [HttpGet("api/v1/environment/{apiKey}/audit-logs")]
+    public async Task<ActionResult<PaginatedResponse<AuditLogResponse>>> ListByEnvironment(
+        string apiKey,
+        [FromQuery] AuditLogFilter filter,
+        CancellationToken ct)
+    {
+        var environment = await environmentService.FindByApiKeyAsync(apiKey, ct);
+        if (environment is null) return NotFound();
+
+        var result = await auditLogQueryService.ListByEnvironmentAsync(environment.Id, filter, ct);
+        return Ok(new PaginatedResponse<AuditLogResponse>(result.Total, null, null, result.Items.ToList()));
+    }
+}

src/api/MicCheck.Api/Audit/AuditService.cs

@@ -4,7 +4,7 @@ using MicCheck.Api.Webhooks;
 
 namespace MicCheck.Api.Audit;
 
-public class AuditService(MicCheckDbContext db, IHttpContextAccessor httpContextAccessor, WebhookQueue webhookQueue)
+public class AuditService(IMicCheckDbContext db, IHttpContextAccessor httpContextAccessor, WebhookQueue webhookQueue)
 {
     private static readonly JsonSerializerOptions JsonOptions = new()
     {