Add path attribute to Tool class for config file tracking

The Tool dataclass now has a path field that points to the config.yaml
file it was loaded from. This is set by load_tool() and enables the
publish dialog to save the registry_hash back to the local config.

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

src/cmdforge/tool.py

@@ -198,6 +198,7 @@ class Tool:
     dependencies: List[str] = field(default_factory=list)  # Required tools for meta-tools
     source: Optional[ToolSource] = None  # Attribution for imported/external tools
     version: str = ""  # Tool version
+    path: Optional[Path] = None  # Path to config.yaml (set by load_tool)
 
     @classmethod
     def from_dict(cls, data: dict) -> "Tool":
@@ -331,7 +332,9 @@ def load_tool(name: str) -> Optional[Tool]:
                 "output": "{response}" if steps else "{input}"
             }
 
-        return Tool.from_dict(data)
+        tool = Tool.from_dict(data)
+        tool.path = config_path
+        return tool
     except yaml.YAMLError as e:
         import sys
         print(f"Error loading tool '{name}': YAML syntax error", file=sys.stderr)