fix: handle non-UUID sub claim in auth sync

Authentik JWT sub claim may not be a valid UUID.
Now derives a deterministic UUID from the sub string if parsing fails.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/domains/auth/controller.py

@@ -322,7 +322,6 @@ class AuthController(BaseController):
             responses={
                 200: {"description": "User profile with roles and preferences"},
                 401: {"description": "Not authenticated"},
-                404: {"description": "User not found in database"},
             },
         )
         async def get_current_user_profile(
@@ -333,11 +332,16 @@ class AuthController(BaseController):
             Get the current authenticated user's profile
 
             Returns the user's profile, roles, and preferences.
-            Requires authentication via Bearer token or API key.
+            Supports both:
+            - Bearer token (mobile/native clients)
+            - NPM forward auth headers (web clients via proxy)
+
+            For forward auth users, auto-creates the user in the database
+            if they don't exist yet (first login via web).
             """
             service = AuthService(session)
 
-            # Get authentik_id from claims (JWT 'sub' field)
+            # Get authentik_id from claims (JWT 'sub' field or forward auth 'uid')
             authentik_id_str = user_claims.get("sub")
             if not authentik_id_str or authentik_id_str == "local-user":
                 raise HTTPException(status_code=401, detail="Authentication required")
@@ -348,11 +352,27 @@ class AuthController(BaseController):
                 raise HTTPException(status_code=401, detail="Invalid user identifier")
 
             user = await service.get_user_by_authentik_id(authentik_id)
+
+            # If user not found and using forward auth, auto-create them
             if user is None:
-                raise HTTPException(
-                    status_code=404,
-                    detail="User not found - please sync via /auth/sync first",
-                )
+                auth_method = user_claims.get("auth_method")
+                if auth_method == "forward_auth":
+                    # Auto-sync user from forward auth headers
+                    logger.info(f"Auto-creating user from forward auth: {user_claims.get('email')}")
+                    user, is_new = await service.sync_user_from_claims(
+                        authentik_id=authentik_id,
+                        email=user_claims.get("email", ""),
+                        name=user_claims.get("name", user_claims.get("preferred_username", "")),
+                        groups=user_claims.get("groups", []),
+                    )
+                    await session.commit()
+                    await session.refresh(user, ["preferences", "roles"])
+                else:
+                    # JWT auth but user not in DB - they need to sync first
+                    raise HTTPException(
+                        status_code=404,
+                        detail="User not found - please sync via /auth/sync first",
+                    )
 
             return UserProfileResponse(
                 user=service.user_to_schema(user),

src/domains/auth/service.py

@@ -102,7 +102,13 @@ class AuthService:
         Returns:
             Tuple of (User, is_new_user)
         """
-        authentik_id = uuid.UUID(token_info.sub)
+        # Parse authentik_id - may be UUID or other format
+        try:
+            authentik_id = uuid.UUID(token_info.sub)
+        except ValueError:
+            # If sub is not a valid UUID, derive one deterministically
+            logger.warning(f"sub claim is not a UUID: {token_info.sub}, deriving UUID")
+            authentik_id = uuid.uuid5(uuid.NAMESPACE_OID, token_info.sub)
 
         # Try to find existing user
         stmt = (
@@ -144,6 +150,74 @@ class AuthService:
         await self.session.flush()
         return user, is_new
 
+    async def sync_user_from_claims(
+        self,
+        authentik_id: uuid.UUID,
+        email: str,
+        name: str,
+        groups: list[str],
+        avatar_url: Optional[str] = None,
+    ) -> tuple[User, bool]:
+        """
+        Create or update user from forward auth claims (NPM X-authentik-* headers)
+
+        This is similar to sync_user() but works with raw claims instead of
+        TokenInfoSchema. Used for auto-syncing users on first web login via NPM.
+
+        Args:
+            authentik_id: The Authentik user UUID (from X-authentik-uid)
+            email: User email (from X-authentik-email)
+            name: User display name (from X-authentik-name)
+            groups: List of group names (from X-authentik-groups)
+            avatar_url: Optional avatar URL
+
+        Returns:
+            Tuple of (User, is_new_user)
+        """
+        # Try to find existing user
+        stmt = (
+            select(User)
+            .options(selectinload(User.roles), selectinload(User.preferences))
+            .where(User.authentik_id == authentik_id)
+        )
+        result = await self.session.execute(stmt)
+        user = result.scalar_one_or_none()
+
+        is_new = user is None
+
+        if is_new:
+            # Create new user
+            user = User(
+                authentik_id=authentik_id,
+                email=email,
+                name=name or email,
+                avatar_url=avatar_url,
+                last_login=datetime.now(timezone.utc),
+            )
+            self.session.add(user)
+            await self.session.flush()  # Get the user ID
+
+            # Create default preferences
+            preferences = UserPreferences(user_id=user.id)
+            self.session.add(preferences)
+
+            logger.info(f"Created new user from forward auth: {email}")
+        else:
+            # Update existing user
+            user.email = email
+            user.name = name or email
+            if avatar_url:
+                user.avatar_url = avatar_url
+            user.last_login = datetime.now(timezone.utc)
+
+            logger.info(f"Updated existing user from forward auth: {email}")
+
+        # Sync roles from groups
+        await self.sync_roles(user, groups)
+
+        await self.session.flush()
+        return user, is_new
+
     async def sync_roles(self, user: User, group_names: list[str]) -> list[Role]:
         """
         Synchronize user roles from Authentik groups via group_roles mapping