a7a45bf8c3
Setting enabled: false at the plugin level (e.g. memory_monitor: {enabled: false})
was silently ignored because the non-dict value was skipped by the metric parser,
leaving THRESHOLD_DEFAULTS entries active.
- _parse_plugin_thresholds: detect plugin-level enabled/enable flag and delete
all matching entries from target_dict (covers legacy and default config paths)
- _parse_multi_config named configs: inject disabled stubs from effective_defaults
into raw_overrides so the merge step overwrites inherited defaults
- Accept 'enable' as a tolerated alias for 'enabled' in both code paths
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>