DEVX-54: fix: squash-merge format uses space not colon after task ID

src/devx/ci/auto_merge.py

@@ -226,12 +226,12 @@ def main(branch: str, pr_title: str, repo: str, pr_number: str) -> None:
     validate_pr_title(pr_title, task_id)
     validate_pr_title_matches_vikunja(pr_title, task_id)
 
-    # Build merge title: DEVX-N: <conventional commit message>
+    # Build merge title: DEVX-N <conventional commit message> (space-separated, no colon)
     commits = client.get_pr_commits(pr_num)
     conv_msg = extract_conventional_msg(commits)
     if not conv_msg:
         raise click.ClickException(_("Could not extract conventional commit message from PR commits."))
-    merge_title = f"{task_id}: {conv_msg}"
+    merge_title = f"{task_id} {conv_msg}"
 
     try:
         client.merge_pr(pr_num, merge_title)

tests/unit/test_auto_merge.py

@@ -221,7 +221,7 @@ class TestMain:
             ["DEVX-19-fix-bug", "DEVX-19: Fix timeout", "owner/repo", "7"],
         )
         assert result.exit_code == 0, result.output
-        mock_client.merge_pr.assert_called_once_with(7, "DEVX-19: fix: resolve timeout")
+        mock_client.merge_pr.assert_called_once_with(7, "DEVX-19 fix: resolve timeout")
 
     @patch.dict("os.environ", {"REPO_TOKEN": ""}, clear=True)
     def test_no_token_raises(self) -> None: