feat: modularize external providers

Tiku.IntegrationTests/ArchitectureBoundaryTests.cs

@@ -39,6 +39,46 @@ public sealed class ArchitectureBoundaryTests
             $"Forbidden tenant-boundary bypasses were found:{Environment.NewLine}{string.Join(Environment.NewLine, violations)}");
     }
 
+    [Fact]
+    public void Business_code_does_not_depend_on_supabase_or_removed_provider_models()
+    {
+        var root = FindRepositoryRoot();
+        var sourceRoots = new[] { "Tiku.Api", "Tiku.Application", "Tiku.Domain", "Tiku.Infrastructure" };
+        var forbidden = new[]
+        {
+            "Supabase",
+            "supabase_storage",
+            "SUPABASE_",
+            "TenantAuthProvider",
+            "TenantPaymentAccount",
+            "TenantPaymentMode",
+            "TenantPaymentAccountStatus",
+            "TenantAuthProviderStatus"
+        };
+
+        var allowedPathFragments = new[]
+        {
+            $"{Path.DirectorySeparatorChar}Persistence{Path.DirectorySeparatorChar}Migrations{Path.DirectorySeparatorChar}"
+        };
+
+        var violations = sourceRoots
+            .SelectMany(directory => Directory.EnumerateFiles(
+                Path.Combine(root, directory),
+                "*.cs",
+                SearchOption.AllDirectories))
+            .Where(path => !allowedPathFragments.Any(fragment => path.Contains(fragment, StringComparison.Ordinal)))
+            .SelectMany(path => File.ReadLines(path)
+                .Select((line, index) => new { path, line, lineNumber = index + 1 }))
+            .Where(candidate => forbidden.Any(symbol =>
+                candidate.line.Contains(symbol, StringComparison.Ordinal)))
+            .Select(candidate => $"{Path.GetRelativePath(root, candidate.path)}:{candidate.lineNumber}")
+            .ToArray();
+
+        Assert.True(
+            violations.Length == 0,
+            $"Forbidden external-provider coupling was found:{Environment.NewLine}{string.Join(Environment.NewLine, violations)}");
+    }
+
     private static string FindRepositoryRoot()
     {
         var directory = new DirectoryInfo(AppContext.BaseDirectory);