DEVX-7: fix: make all warnings into errors across devx tools

tests/unit/test_post_merge.py

@@ -132,13 +132,12 @@ class TestMain:
         assert "VIKUNJA_TOKEN" in result.output
 
     @patch.dict("os.environ", {"VIKUNJA_TOKEN": "tok"})
-    def test_no_task_id_non_release_warns(self) -> None:
-        """Non-release commits without DEVX-N prefix should warn, not fail."""
+    def test_no_task_id_non_release_fails(self) -> None:
+        """Non-release commits without DEVX-N prefix should fail."""
         runner = CliRunner()
         result = runner.invoke(main, ["fix: resolve bug"])
-        assert result.exit_code == 0
+        assert result.exit_code != 0
         assert "No task ID" in result.output
-        assert "Skipping" in result.output
 
     @patch.dict("os.environ", {"VIKUNJA_TOKEN": "tok"})
     def test_release_commit_without_task_id_skips(self) -> None:
@@ -179,8 +178,8 @@ class TestMain:
 
     @patch.dict("os.environ", {"VIKUNJA_TOKEN": "tok"})
     @patch("devx.ci.post_merge.VikunjaClient")
-    def test_post_comment_failure_warns(self, mock_client_cls: MagicMock) -> None:
-        """Vikunja API errors should warn, not fail — the merge already succeeded."""
+    def test_post_comment_failure_fails(self, mock_client_cls: MagicMock) -> None:
+        """Vikunja API errors should fail — the task was not updated."""
         mock_client = MagicMock()
         mock_client.list_project_tasks.return_value = [
             {"id": 267, "identifier": "DEVX-20"},
@@ -189,14 +188,13 @@ class TestMain:
         mock_client_cls.return_value = mock_client
         runner = CliRunner()
         result = runner.invoke(main, ["DEVX-20: fix: bug"])
-        assert result.exit_code == 0
-        assert "Warning" in result.output
-        assert "not updated" in result.output.lower()
+        assert result.exit_code != 0
+        assert "Vikunja API error" in result.output
 
     @patch.dict("os.environ", {"VIKUNJA_TOKEN": "tok"})
     @patch("devx.ci.post_merge.VikunjaClient")
-    def test_mark_done_failure_warns(self, mock_client_cls: MagicMock) -> None:
-        """Vikunja API errors should warn, not fail — the merge already succeeded."""
+    def test_mark_done_failure_fails(self, mock_client_cls: MagicMock) -> None:
+        """Vikunja API errors should fail — the task was not updated."""
         mock_client = MagicMock()
         mock_client.list_project_tasks.return_value = [
             {"id": 267, "identifier": "DEVX-20"},
@@ -206,9 +204,8 @@ class TestMain:
         mock_client_cls.return_value = mock_client
         runner = CliRunner()
         result = runner.invoke(main, ["DEVX-20: fix: bug"])
-        assert result.exit_code == 0
-        assert "Warning" in result.output
-        assert "not updated" in result.output.lower()
+        assert result.exit_code != 0
+        assert "Vikunja API error" in result.output
 
 
 class TestGetGitCommitMessage: