fix(extensions): preserve installed_at in enable/disable, narrow exception handling

- extension_enable: Update registry directly instead of calling add()
  to preserve the original installed_at timestamp
- extension_disable: Same fix - direct registry update preserves timestamp
- extension_list --available/--all: Narrow exception handler from
  Exception to ExtensionError, let KeyboardInterrupt propagate

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: iamaeroplane

src/specify_cli/__init__.py

@@ -2017,7 +2017,9 @@ def extension_list(
             elif available and not all_extensions:
                 console.print("\n[yellow]No uninstalled extensions in catalog[/yellow]")
                 console.print("\nAll catalog extensions are already installed.")
-        except Exception as e:
+        except KeyboardInterrupt:
+            raise
+        except ExtensionError as e:
             console.print(f"\n[yellow]Warning:[/yellow] Could not fetch catalog: {e}")
             if available and not installed:
                 console.print("\nInstall an extension with:")
@@ -2704,7 +2706,9 @@ def extension_enable(
         raise typer.Exit(0)
 
     metadata["enabled"] = True
-    manager.registry.add(extension_id, metadata)
+    # Update registry directly to preserve installed_at (add() would overwrite it)
+    manager.registry.data["extensions"][extension_id] = metadata
+    manager.registry._save()
 
     # Enable hooks in extensions.yml
     config = hook_executor.get_project_config()
@@ -2753,7 +2757,9 @@ def extension_disable(
         raise typer.Exit(0)
 
     metadata["enabled"] = False
-    manager.registry.add(extension_id, metadata)
+    # Update registry directly to preserve installed_at (add() would overwrite it)
+    manager.registry.data["extensions"][extension_id] = metadata
+    manager.registry._save()
 
     # Disable hooks in extensions.yml
     config = hook_executor.get_project_config()