Add service_documentation to OAuth metadata

- Point Claude to correct MCP endpoint path /mcp/
- This should fix the 405 Method Not Allowed errors
- OAuth metadata now includes service_documentation field

🤖 Generated with [Claude Code](https://claude.ai/code)

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

mcp_auth_http_adapter.py

@@ -42,7 +42,8 @@ async def get_oauth_metadata():
         "grant_types_supported": ["authorization_code", "refresh_token"],
         "code_challenge_methods_supported": ["S256"],
         "token_endpoint_auth_methods_supported": ["none"],
-        "scopes_supported": ["mcp:tools:read", "mcp:tools:write", "openid", "profile", "email"]
+        "scopes_supported": ["mcp:tools:read", "mcp:tools:write", "openid", "profile", "email"],
+        "service_documentation": f"{BASE_URL}/mcp/"
     })