fix: document skip_reason in Plugin docstring; remove unused import in test

hbd/client/plugin.py

@@ -22,13 +22,14 @@ from typing import Any, Dict, List, Optional, Type
 
 class Plugin(ABC):
     """Base class for all plugins.
-    
+
     Attributes:
         name: Unique plugin identifier (e.g., "os_info", "cpu_monitor")
         version: Plugin version string
         description: Human-readable description
         interval: Collection interval in seconds (0 for InfoPlugin = collect once)
         enabled: Whether plugin is active (can be disabled via config)
+        skip_reason: Optional[str] = None  # Set before returning False from initialize() so loader logs INFO not WARNING
     """
     
     name: str = ""

tests/test_plugin.py

@@ -2,7 +2,7 @@ import asyncio
 import logging
 import textwrap
 
-from hbd.client.plugin import Plugin, PluginLoader, PluginRegistry
+from hbd.client.plugin import PluginLoader, PluginRegistry
 
 
 def test_plugin_skip_reason_defaults_none(tmp_path):