fix: address PR review feedback on --force implementation

- Remove unused `backup_config_dir` variable assignment (Ruff F841)
- Defer `remove()` until after `_validate_install_conflicts()` to prevent
  data loss if validation fails mid-reinstall
- Use `TemporaryDirectory` instead of `NamedTemporaryFile` in ZIP test
  to avoid Windows file-locking failures

Author: grissiom

src/specify_cli/extensions.py

@@ -1164,12 +1164,7 @@ def install_from_directory(
 
         # Check if already installed
         if self.registry.is_installed(manifest.id):
-            if force:
-                # Remove existing extension first (handles command/skill/hook
-                # cleanup, config backup, and registry removal).
-                backup_config_dir = self.extensions_dir / ".backup" / manifest.id
-                self.remove(manifest.id)
-            else:
+            if not force:
                 raise ExtensionError(
                     f"Extension '{manifest.id}' is already installed. "
                     f"Use 'specify extension remove {manifest.id}' first, "
@@ -1179,6 +1174,12 @@ def install_from_directory(
         # Reject manifests that would shadow core commands or installed extensions.
         self._validate_install_conflicts(manifest)
 
+        # Remove existing installation AFTER all validations pass so that a
+        # validation failure doesn't leave the user with a half-uninstalled
+        # extension (configs stranded in .backup/).
+        if force and self.registry.is_installed(manifest.id):
+            self.remove(manifest.id)
+
         # Install extension
         dest_dir = self.extensions_dir / manifest.id
         if dest_dir.exists():

tests/test_extensions.py

@@ -848,9 +848,10 @@ def test_install_zip_force_reinstall(self, extension_dir, project_dir):
         # Install once from directory
         manager.install_from_directory(extension_dir, "0.1.0", register_commands=False)
 
-        # Create a ZIP of the extension
-        with tempfile.NamedTemporaryFile(suffix=".zip") as tmp:
-            zip_path = Path(tmp.name)
+        # Create a ZIP of the extension in a temp directory (not NamedTemporaryFile,
+        # which can fail on Windows due to file locking).
+        with tempfile.TemporaryDirectory() as tmpdir:
+            zip_path = Path(tmpdir) / "test-ext.zip"
             with zipfile.ZipFile(zip_path, "w") as zf:
                 for f in extension_dir.rglob("*"):
                     if f.is_file():