feat(api): .NET 10 multi-tenant REST API

Full backend implementation:
- Multi-tenant cafe/restaurant management (menus, orders, tables, staff)
- POS order flow with ZarinPal and Snappfood payment integration
- OTP authentication via Kavenegar SMS
- QR digital menu with public discover/finder endpoints
- Customer loyalty, coupons, CRM
- PostgreSQL via EF Core, Redis for caching/sessions
- Background jobs, webhook handlers
- Full migration history

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tests/Meezi.API.Tests/BranchPhaseATests.cs

@@ -0,0 +1,27 @@
+using Meezi.API.Models.Branches;
+using Meezi.API.Validators;
+using Meezi.Core.Utilities;
+using Xunit;
+
+namespace Meezi.API.Tests;
+
+public class BranchPhaseATests
+{
+    [Fact]
+    public void CreateBranchRequestValidator_requires_valid_login_phone()
+    {
+        var validator = new CreateBranchRequestValidator();
+        var invalid = validator.Validate(new CreateBranchRequest("شعبه", "123", null, null, null, null));
+        Assert.False(invalid.IsValid);
+
+        var valid = validator.Validate(new CreateBranchRequest("شعبه", "09121234567", "علی", null, null, null));
+        Assert.True(valid.IsValid);
+    }
+
+    [Fact]
+    public void PhoneNormalizer_aligns_branch_login_phones()
+    {
+        Assert.Equal("09121234567", PhoneNormalizer.Normalize("0912 123 4567"));
+        Assert.Equal("09121234567", PhoneNormalizer.Normalize("+989121234567"));
+    }
+}