feat(mcp): add per-server tool allowlist policy module and allowedTools config field

src/config/mcp_factory.rs

@@ -139,6 +139,7 @@ mod tests {
             url: None,
             headers: None,
             oauth: None,
+            allowed_tools: None,
         }
     }
 
@@ -156,6 +157,7 @@ mod tests {
             url: Some(url.to_string()),
             headers,
             oauth: None,
+            allowed_tools: None,
         }
     }