feat: RBAC Phase 1 — consolidate user roles into 4-value enum

Consolidate User.role (2-value: admin/store) + User.is_super_admin (boolean)
into a single 4-value UserRole enum: super_admin, platform_admin,
merchant_owner, store_member. Drop stale StoreUser.user_type column.
Fix role="user" bug in merchant creation.

Key changes:
- Expand UserRole enum from 2 to 4 values with computed properties
  (is_admin, is_super_admin, is_platform_admin, is_merchant_owner, is_store_user)
- Add Alembic migration (tenancy_003) for data migration + column drops
- Remove is_super_admin from JWT token payload
- Update all auth dependencies, services, routes, templates, JS, and tests
- Update all RBAC documentation

66 files changed, 1219 unit tests passing.

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

app/modules/tenancy/routes/api/admin_users.py

@@ -57,7 +57,7 @@ class AdminUserResponse(BaseModel):
     first_name: str | None = None
     last_name: str | None = None
     is_active: bool
-    is_super_admin: bool
+    role: str
     platform_assignments: list[PlatformAssignmentResponse] = []
     created_at: datetime
     updated_at: datetime
@@ -82,7 +82,7 @@ class CreateAdminUserRequest(BaseModel):
     password: str
     first_name: str | None = None
     last_name: str | None = None
-    is_super_admin: bool = False
+    role: str = "platform_admin"
     platform_ids: list[int] = []
 
 
@@ -93,9 +93,9 @@ class AssignPlatformRequest(BaseModel):
 
 
 class ToggleSuperAdminRequest(BaseModel):
-    """Request to toggle super admin status."""
+    """Request to change admin role (super_admin or platform_admin)."""
 
-    is_super_admin: bool
+    role: str  # "super_admin" or "platform_admin"
 
 
 # ============================================================================
@@ -125,7 +125,7 @@ def _build_admin_response(admin: User) -> AdminUserResponse:
         first_name=admin.first_name,
         last_name=admin.last_name,
         is_active=admin.is_active,
-        is_super_admin=admin.is_super_admin,
+        role=admin.role,
         platform_assignments=assignments,
         created_at=admin.created_at,
         updated_at=admin.updated_at,
@@ -174,14 +174,14 @@ def create_admin_user(
 
     Super admin only.
     """
-    # Validate platform_ids required for non-super admin
-    if not request.is_super_admin and not request.platform_ids:
+    # Validate platform_ids required for platform admins
+    if request.role != "super_admin" and not request.platform_ids:
         raise ValidationException(
             "Platform admins must be assigned to at least one platform",
             field="platform_ids",
         )
 
-    if request.is_super_admin:
+    if request.role == "super_admin":
         # Create super admin using service
         user = admin_platform_service.create_super_admin(
             db=db,
@@ -202,7 +202,7 @@ def create_admin_user(
             first_name=user.first_name,
             last_name=user.last_name,
             is_active=user.is_active,
-            is_super_admin=user.is_super_admin,
+            role=user.role,
             platform_assignments=[],
         )
     # Create platform admin with assignments using service
@@ -306,17 +306,17 @@ def toggle_super_admin_status(
     user = admin_platform_service.toggle_super_admin(
         db=db,
         user_id=user_id,
-        is_super_admin=request.is_super_admin,
+        is_super_admin=(request.role == "super_admin"),
         current_admin_id=current_admin.id,
     )
     db.commit()
 
-    action = "promoted to" if request.is_super_admin else "demoted from"
+    action = "promoted to" if request.role == "super_admin" else "demoted from"
 
     return {
         "message": f"Admin {action} super admin successfully",
         "user_id": user_id,
-        "is_super_admin": user.is_super_admin,
+        "role": user.role,
     }