Fix list_tools and load_tool to handle owner subdirectories

Tools from the registry are installed to ~/.cmdforge/owner/name/ (e.g.,
~/.cmdforge/official/summarize/), but list_tools() only searched direct
children of ~/.cmdforge/.

Changes:
- list_tools() now searches both direct children and owner subdirectories
- Returns qualified names for nested tools (e.g., "official/summarize")
- load_tool() already handled qualified paths, added docstring clarification

Fixes tools installed via `cmdforge install` not appearing in `cmdforge list`.

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

src/cmdforge/tool.py

@@ -290,22 +290,49 @@ def get_bin_dir() -> Path:
 
 
 def list_tools() -> list[str]:
-    """List all available tools."""
+    """List all available tools.
+
+    Returns tools from:
+    - Direct children: ~/.cmdforge/<name>/config.yaml
+    - Owner subdirectories: ~/.cmdforge/<owner>/<name>/config.yaml
+    """
     tools_dir = get_tools_dir()
     tools = []
 
+    if not tools_dir.exists():
+        return tools
+
     for item in tools_dir.iterdir():
         if item.is_dir():
             config = item / "config.yaml"
             if config.exists():
+                # Direct tool (e.g., ~/.cmdforge/my-tool/)
                 tools.append(item.name)
+            else:
+                # Check if this is an owner directory with nested tools
+                # (e.g., ~/.cmdforge/official/summarize/)
+                for subitem in item.iterdir():
+                    if subitem.is_dir():
+                        subconfig = subitem / "config.yaml"
+                        if subconfig.exists():
+                            # Qualified name: owner/name
+                            tools.append(f"{item.name}/{subitem.name}")
 
     return sorted(tools)
 
 
 def load_tool(name: str) -> Optional[Tool]:
-    """Load a tool by name."""
-    config_path = get_tools_dir() / name / "config.yaml"
+    """Load a tool by name.
+
+    Args:
+        name: Tool name, can be:
+            - Simple: "my-tool" (looks in ~/.cmdforge/my-tool/)
+            - Qualified: "official/summarize" (looks in ~/.cmdforge/official/summarize/)
+    """
+    tools_dir = get_tools_dir()
+
+    # Try direct path first (handles both simple and qualified names)
+    config_path = tools_dir / name / "config.yaml"
 
     if not config_path.exists():
         return None