Add unit tests for 9 new services/controllers and expand existing test coverage

116 tests passing: JobPhotoService, MeasurementConversionService, PlatformSettingsService,
QuoteApprovalController, QuotePhotoService, ShopCapabilityCalculator, StorageMigrationService,
TenantContext, UsageQuotaController — plus expanded PricingCalculation, Registration, and
Subscription tests.

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

tests/PowderCoating.UnitTests/PlatformSettingsServiceTests.cs

@@ -0,0 +1,100 @@
+using Microsoft.EntityFrameworkCore;
+using PowderCoating.Core.Entities;
+using PowderCoating.Infrastructure.Data;
+using PowderCoating.Infrastructure.Services;
+
+namespace PowderCoating.UnitTests;
+
+public class PlatformSettingsServiceTests
+{
+    [Fact]
+    public async Task GetAsync_ReturnsStoredValue()
+    {
+        await using var context = CreateContext();
+        context.PlatformSettings.Add(new PlatformSetting
+        {
+            Key = "BrandName",
+            Value = "Powder Coating Pro"
+        });
+        await context.SaveChangesAsync();
+
+        var service = new PlatformSettingsService(context);
+
+        var value = await service.GetAsync("BrandName");
+
+        Assert.Equal("Powder Coating Pro", value);
+    }
+
+    [Fact]
+    public async Task GetAsync_WhenMissing_ReturnsNull()
+    {
+        await using var context = CreateContext();
+        var service = new PlatformSettingsService(context);
+
+        var value = await service.GetAsync("MissingKey");
+
+        Assert.Null(value);
+    }
+
+    [Fact]
+    public async Task SetAsync_WhenSettingExists_UpdatesValueAndAuditFields()
+    {
+        await using var context = CreateContext();
+        context.PlatformSettings.Add(new PlatformSetting
+        {
+            Key = "TrialsEnabled",
+            Value = "true",
+            UpdatedBy = "old-user"
+        });
+        await context.SaveChangesAsync();
+
+        var service = new PlatformSettingsService(context);
+
+        await service.SetAsync("TrialsEnabled", "false", "superadmin@example.com");
+
+        var setting = await context.PlatformSettings.SingleAsync();
+        Assert.Equal("false", setting.Value);
+        Assert.Equal("superadmin@example.com", setting.UpdatedBy);
+        Assert.True(setting.UpdatedAt.HasValue);
+    }
+
+    [Fact]
+    public async Task SetAsync_WhenSettingMissing_InsertsRow()
+    {
+        await using var context = CreateContext();
+        var service = new PlatformSettingsService(context);
+
+        await service.SetAsync("SupportEmail", "help@example.com", "setup");
+
+        var setting = await context.PlatformSettings.SingleAsync();
+        Assert.Equal("SupportEmail", setting.Key);
+        Assert.Equal("help@example.com", setting.Value);
+        Assert.Equal("setup", setting.UpdatedBy);
+    }
+
+    [Fact]
+    public async Task GetAllAsync_OrdersByGroupThenKey()
+    {
+        await using var context = CreateContext();
+        context.PlatformSettings.AddRange(
+            new PlatformSetting { Key = "Zeta", GroupName = "Billing", Value = "1" },
+            new PlatformSetting { Key = "Alpha", GroupName = "Billing", Value = "2" },
+            new PlatformSetting { Key = "Bravo", GroupName = "Alerts", Value = "3" });
+        await context.SaveChangesAsync();
+
+        var service = new PlatformSettingsService(context);
+
+        var settings = await service.GetAllAsync();
+
+        Assert.Equal(new[] { "Bravo", "Alpha", "Zeta" }, settings.Select(s => s.Key).ToArray());
+    }
+
+    private static ApplicationDbContext CreateContext()
+    {
+        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
+            .UseInMemoryDatabase(Guid.NewGuid().ToString())
+            .Options;
+
+        return new ApplicationDbContext(options);
+    }
+}