PR #63 code-review caught that the SDK copy of AgentskillsAdaptor uses
json.loads/json.dumps in _merge_settings_fragment + _rewrite_hook_paths
+ _deep_merge_hooks but never imports json. The runtime copy
(workspace-template/plugins_registry/builtins.py) already has the
import; this brings the SDK side in line.
Bug surfaces only when a plugin shipping settings-fragment.json (any
of the 5 hook plugins or 2 workflow plugins in this PR) is installed
through the SDK path — would NameError on the first json.loads call.
The drift test catches behavioral drift via fixture install scenarios
but not import-level drift in helper code paths.
Verified: json is now importable (`hasattr(molecule_plugin.builtins,
'json')` → True), drift test still passes.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>