docs: bring docforge docstrings and wiki to GSDFC standard

- fix GSDFC spec contradictions in __init__ docstring (parenthesized types, fenced-block rule) and sync generated README
- rewrite docstrings across loaders, models, nav, servers, renderers, cli; sync .pyi stubs
- add pydoclint (google style) gate to dev extras and pyproject config
- fix mcp nav resources doc:// -> docs://
- refresh docs/lib and docs/mcp, drop stale docforge/ duplicate group
- update wiki pages and add GSDFC + MCP guides under 05_development

docforge/servers/mcp_server.pyi

@@ -4,7 +4,10 @@ from typing import Any, Literal
 from mcp.server.fastmcp import FastMCP
 
 class MCPServer:
-    """MCP server for serving documentation."""
+    """MCP server serving a pre-generated documentation bundle.
+
+    Exposes read-only documentation resources and a health-check tool.
+    """
 
     mcp_root: Path
     app: FastMCP