fix: greetd-Session nach Auth-Fehler sauber canceln

Nach fehlgeschlagenem Login (falsches Passwort) wurde die greetd-Session
nicht gecancelt — beim nächsten Versuch kam "a session is already being
configured". Jetzt wird cancel_session gesendet nach Auth-Fehler, und
bei create_session-Fehler wird einmal cancel + retry versucht.

Außerdem: GTK-Theme-Name und PKGBUILD-pkgver aktualisiert.

tests/test_integration.py

@@ -112,12 +112,13 @@ class TestLoginFlow:
         assert mock.received[1] == {"type": "post_auth_message_response", "response": "geheim"}
         assert mock.received[2] == {"type": "start_session", "cmd": ["Hyprland"]}
 
-    def test_wrong_password(self, tmp_path: Path) -> None:
-        """Simulate a failed login due to wrong password."""
+    def test_wrong_password_sends_cancel(self, tmp_path: Path) -> None:
+        """After a failed login, cancel_session must be sent to free the greetd session."""
         sock_path = tmp_path / "greetd.sock"
         mock = MockGreetd(sock_path)
         mock.expect({"type": "auth_message", "auth_message_type": "secret", "auth_message": "Password:"})
         mock.expect({"type": "error", "error_type": "auth_error", "description": "Authentication failed"})
+        mock.expect({"type": "success"})  # Response to cancel_session
         mock.start()
 
         try:
@@ -131,10 +132,64 @@ class TestLoginFlow:
             assert response["type"] == "error"
             assert response["description"] == "Authentication failed"
 
+            # The greeter must cancel the session after auth failure
+            response = cancel_session(sock)
+            assert response["type"] == "success"
+
             sock.close()
         finally:
             mock.stop()
 
+        assert mock.received[2] == {"type": "cancel_session"}
+
+    def test_stale_session_cancel_and_retry(self, tmp_path: Path) -> None:
+        """When create_session fails due to a stale session, cancel and retry."""
+        sock_path = tmp_path / "greetd.sock"
+        mock = MockGreetd(sock_path)
+        # First create_session → error (stale session)
+        mock.expect({"type": "error", "error_type": "error", "description": "a session is already being configured"})
+        # cancel_session → success
+        mock.expect({"type": "success"})
+        # Second create_session → auth_message (retry succeeds)
+        mock.expect({"type": "auth_message", "auth_message_type": "secret", "auth_message": "Password:"})
+        # post_auth_response → success
+        mock.expect({"type": "success"})
+        # start_session → success
+        mock.expect({"type": "success"})
+        mock.start()
+
+        try:
+            sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+            sock.connect(str(sock_path))
+
+            # Step 1: Create session fails
+            response = create_session(sock, "dominik")
+            assert response["type"] == "error"
+
+            # Step 2: Cancel stale session
+            response = cancel_session(sock)
+            assert response["type"] == "success"
+
+            # Step 3: Retry create session
+            response = create_session(sock, "dominik")
+            assert response["type"] == "auth_message"
+
+            # Step 4: Send password
+            response = post_auth_response(sock, "geheim")
+            assert response["type"] == "success"
+
+            # Step 5: Start session
+            response = start_session(sock, ["niri-session"])
+            assert response["type"] == "success"
+
+            sock.close()
+        finally:
+            mock.stop()
+
+        assert mock.received[0] == {"type": "create_session", "username": "dominik"}
+        assert mock.received[1] == {"type": "cancel_session"}
+        assert mock.received[2] == {"type": "create_session", "username": "dominik"}
+
     def test_multi_stage_auth_sends_cancel(self, tmp_path: Path) -> None:
         """When greetd sends a second auth_message after password, cancel the session."""
         sock_path = tmp_path / "greetd.sock"