Add the MCP server inspector page

Admin-only page at /mcp showing the server's connection details, a
copy-pasteable client config, and every tool with its arguments - plus a console
to run one against live data and see what an AI client would get back.

It talks to /api/mcp/*, not to the /mcp endpoint directly. That endpoint speaks
streamable HTTP with session handling, and implementing a client for it in the
browser purely to render a tool list would be a lot of machinery for a read-only
admin screen.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/api/client.js

@@ -289,6 +289,18 @@ export const api = {
     }),
 
   uploadUserProductsFile: (file) => upload('/api/user/products/upload-file', file),
+
+  // --- MCP (Model Context Protocol) ---
+  // The /mcp endpoint itself speaks streamable HTTP with sessions, which the
+  // browser can't talk to without a full MCP client. These two REST endpoints
+  // expose the same server for the admin page - see app/api/routers/mcp_info.py.
+  getMcpInfo: () => request('/api/mcp/info'),
+
+  invokeMcpTool: (toolName, args = {}) =>
+    request(`/api/mcp/tools/${encodeURIComponent(toolName)}`, {
+      method: 'POST',
+      body: JSON.stringify(args),
+    }),
 };
 
 export { ApiError };