feat(thalos-domain): add provider-aware policy invariants

docs/migration/policy-behavior-invariants.md

@@ -3,6 +3,9 @@
 ## Invariants
 - Equivalent policy inputs produce equivalent policy decisions.
 - Token decision fallback behavior remains stable until explicitly revised.
+- Provider semantics are explicit:
+  - `InternalJwt`: standard identity permission evaluation.
+  - `AzureAd` and `Google`: policy permission must remain within `identity.*` scope.
 - Service transport contracts remain stable during domain extraction.
 
 ## Validation Approach

src/Thalos.Domain/Contracts/IdentityPolicyContextData.cs

@@ -1,3 +1,5 @@
+using BuildingBlock.Identity.Contracts.Conventions;
+
 namespace Thalos.Domain.Contracts;
 
 /// <summary>
@@ -5,10 +7,12 @@ namespace Thalos.Domain.Contracts;
 /// </summary>
 /// <param name="SubjectId">Identity subject identifier.</param>
 /// <param name="PermissionCode">Permission code being evaluated.</param>
+/// <param name="Provider">Auth provider used in the request flow.</param>
 /// <param name="ContextSatisfied">Whether contextual constraints are satisfied.</param>
 /// <param name="GrantedPermissions">Permissions granted to subject in tenant scope.</param>
 public sealed record IdentityPolicyContextData(
     string SubjectId,
     string PermissionCode,
+    IdentityAuthProvider Provider,
     bool ContextSatisfied,
     IReadOnlyCollection<string> GrantedPermissions);

src/Thalos.Domain/Contracts/IdentityTokenData.cs

@@ -1,3 +1,5 @@
+using BuildingBlock.Identity.Contracts.Conventions;
+
 namespace Thalos.Domain.Contracts;
 
 /// <summary>
@@ -5,4 +7,8 @@ namespace Thalos.Domain.Contracts;
 /// </summary>
 /// <param name="Token">Token value, if found.</param>
 /// <param name="ExpiresInSeconds">Token lifetime, if found.</param>
-public sealed record IdentityTokenData(string? Token, int? ExpiresInSeconds);
+/// <param name="Provider">Auth provider used in the issuance flow.</param>
+public sealed record IdentityTokenData(
+    string? Token,
+    int? ExpiresInSeconds,
+    IdentityAuthProvider Provider = IdentityAuthProvider.InternalJwt);

src/Thalos.Domain/Decisions/IdentityPolicyDecisionService.cs

@@ -1,5 +1,6 @@
 using BuildingBlock.Identity.Contracts.Requests;
 using BuildingBlock.Identity.Contracts.Responses;
+using BuildingBlock.Identity.Contracts.Conventions;
 using Thalos.Domain.Contracts;
 
 namespace Thalos.Domain.Decisions;
@@ -12,7 +13,11 @@ public sealed class IdentityPolicyDecisionService : IIdentityPolicyDecisionServi
     /// <inheritdoc />
     public IdentityPolicyContextRequest BuildPolicyContextRequest(EvaluateIdentityPolicyRequest request)
     {
-        return new IdentityPolicyContextRequest(request.SubjectId, request.TenantId, request.PermissionCode);
+        return new IdentityPolicyContextRequest(
+            request.SubjectId,
+            request.TenantId,
+            request.PermissionCode,
+            request.Provider);
     }
 
     /// <inheritdoc />
@@ -22,10 +27,33 @@ public sealed class IdentityPolicyDecisionService : IIdentityPolicyDecisionServi
     {
         var permissionMatched = policyContextData.GrantedPermissions.Any(permission =>
             string.Equals(permission, request.PermissionCode, StringComparison.OrdinalIgnoreCase));
+        var providerSatisfied = IsProviderContextSatisfied(request.Provider, policyContextData);
 
         return new EvaluateIdentityPolicyResponse(
             request.SubjectId,
             request.PermissionCode,
-            policyContextData.ContextSatisfied && permissionMatched);
+            providerSatisfied && permissionMatched);
+    }
+
+    private static bool IsProviderContextSatisfied(
+        IdentityAuthProvider provider,
+        IdentityPolicyContextData policyContextData)
+    {
+        if (!policyContextData.ContextSatisfied)
+        {
+            return false;
+        }
+
+        return provider switch
+        {
+            IdentityAuthProvider.InternalJwt => true,
+            IdentityAuthProvider.AzureAd => policyContextData.PermissionCode.StartsWith(
+                "identity.",
+                StringComparison.OrdinalIgnoreCase),
+            IdentityAuthProvider.Google => policyContextData.PermissionCode.StartsWith(
+                "identity.",
+                StringComparison.OrdinalIgnoreCase),
+            _ => false
+        };
     }
 }

tests/Thalos.Domain.UnitTests/IdentityPolicyDecisionServiceTests.cs

@@ -1,4 +1,5 @@
 using BuildingBlock.Identity.Contracts.Requests;
+using BuildingBlock.Identity.Contracts.Conventions;
 using Thalos.Domain.Contracts;
 using Thalos.Domain.Decisions;
 
@@ -10,10 +11,15 @@ public class IdentityPolicyDecisionServiceTests
     public void Evaluate_WhenPermissionMatchedAndContextSatisfied_ReturnsAllowed()
     {
         var service = new IdentityPolicyDecisionService();
-        var request = new EvaluateIdentityPolicyRequest("user-1", "tenant-1", "identity.token.issue");
+        var request = new EvaluateIdentityPolicyRequest(
+            "user-1",
+            "tenant-1",
+            "identity.token.issue",
+            IdentityAuthProvider.InternalJwt);
         var context = new IdentityPolicyContextData(
             request.SubjectId,
             request.PermissionCode,
+            request.Provider,
             true,
             ["identity.token.issue", "identity.policy.evaluate"]);
 
@@ -26,8 +32,38 @@ public class IdentityPolicyDecisionServiceTests
     public void Evaluate_WhenPermissionMissing_ReturnsDenied()
     {
         var service = new IdentityPolicyDecisionService();
-        var request = new EvaluateIdentityPolicyRequest("user-1", "tenant-1", "identity.token.issue");
-        var context = new IdentityPolicyContextData(request.SubjectId, request.PermissionCode, true, ["identity.read"]);
+        var request = new EvaluateIdentityPolicyRequest(
+            "user-1",
+            "tenant-1",
+            "identity.token.issue",
+            IdentityAuthProvider.InternalJwt);
+        var context = new IdentityPolicyContextData(
+            request.SubjectId,
+            request.PermissionCode,
+            request.Provider,
+            true,
+            ["identity.read"]);
+
+        var response = service.Evaluate(request, context);
+
+        Assert.False(response.IsAllowed);
+    }
+
+    [Fact]
+    public void Evaluate_WhenProviderIsExternalAndPermissionPrefixInvalid_ReturnsDenied()
+    {
+        var service = new IdentityPolicyDecisionService();
+        var request = new EvaluateIdentityPolicyRequest(
+            "user-2",
+            "tenant-2",
+            "catalog.read",
+            IdentityAuthProvider.AzureAd);
+        var context = new IdentityPolicyContextData(
+            request.SubjectId,
+            request.PermissionCode,
+            request.Provider,
+            true,
+            ["catalog.read"]);
 
         var response = service.Evaluate(request, context);