fix: narrow bare except Exception in VS Code settings merge (#3844)

* fix: narrow bare except Exception in VS Code settings merge

Replace overly broad except Exception with (OSError, ValueError, KeyError)
to let programming errors like TypeError or AttributeError propagate while
still handling expected I/O and parse errors gracefully.

* test: verify programming errors propagate through handle_vscode_settings

The narrow exception change from 'except Exception' to
'except (OSError, ValueError, KeyError)' was not covered by a
regression test. Add a test that monkeypatches merge_json_files to
raise TypeError and verifies it propagates rather than being swallowed.

Author: Quratulain-bilal

src/specify_cli/_utils.py

@@ -213,7 +213,7 @@ def atomic_write_json(target_file: Path, payload: dict[str, Any]) -> None:
             shutil.copy2(sub_item, dest_file)
             log("Copied (no existing settings.json):", "blue")
 
-    except Exception as e:
+    except (OSError, ValueError, KeyError) as e:
         log(f"Warning: Could not merge settings: {e}", "yellow")
         if not dest_file.exists():
             shutil.copy2(sub_item, dest_file)

tests/test_merge.py

@@ -1,5 +1,7 @@
 import stat
 
+import pytest
+
 from specify_cli import merge_json_files
 from specify_cli import handle_vscode_settings
 
@@ -188,3 +190,25 @@ def test_handle_vscode_settings_preserves_mode_on_atomic_write(tmp_path):
 
     after_mode = stat.S_IMODE(dest_file.stat().st_mode)
     assert after_mode == before_mode
+
+
+def test_handle_vscode_settings_propagates_programming_errors(tmp_path):
+    """Unexpected programming errors (TypeError) must propagate, not be silently swallowed."""
+    vscode_dir = tmp_path / ".vscode"
+    vscode_dir.mkdir()
+    dest_file = vscode_dir / "settings.json"
+    dest_file.write_text('{"a": 1}\n', encoding="utf-8")
+    template_file = tmp_path / "template_settings.json"
+    template_file.write_text('{"b": 2}\n', encoding="utf-8")
+
+    import specify_cli._utils as utils_mod
+    original_merge = utils_mod.merge_json_files
+    utils_mod.merge_json_files = lambda *a, **kw: (_ for _ in ()).throw(TypeError("boom"))
+    try:
+        with pytest.raises(TypeError):
+            handle_vscode_settings(
+                template_file, dest_file, "settings.json",
+                verbose=False, tracker=None,
+            )
+    finally:
+        utils_mod.merge_json_files = original_merge