fix(mcp): require the panel key for panel requests

panel_request now requires a key that each MCP server generates and places
in its panel page, which keeps the tool from clients that list it to the
model without loading the panel. The key is not access control: any MCP
client can read the panel page. Routes the panel never loads (provider
settings, credential and model endpoints, the MCP endpoint and development
server internals) are refused to every caller, regardless of letter case or
encoding.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

src/app/globePanelRuntime.js

@@ -45,7 +45,8 @@ export function panelRuntime(config) {
     try {
       const result = await request('tools/call', {
         name: config.toolName,
-        arguments: args,
+        // The server refuses the panel's requests without its key.
+        arguments: { ...args, key: config.panelKey },
       });
       if (result?.isError || !result?.structuredContent)
         throw new Error(result?.content?.[0]?.text || 'The request failed');