fix(mcp): support underscore-based file tools (fs_read, fs_write, fs_delete) for thin client

vibn-frontend/app/api/mcp/route.ts

@@ -429,12 +429,15 @@ export async function POST(request: Request) {
       case "shell.exec":
         return await toolShellExec(principal, params);
       case "fs.read":
+      case "fs_read":
         return await toolFsRead(principal, params);
       case "request_visual_qa":
         return await toolRequestVisualQA(principal, params);
       case "fs.write":
+      case "fs_write":
         return await toolFsWrite(principal, params);
       case "fs.edit":
+      case "fs_edit":
         return await toolFsEdit(principal, params);
       case "get_design_template":
         return await toolGetDesignTemplate(params);
@@ -443,15 +446,19 @@ export async function POST(request: Request) {
       case "generate_media":
         return await toolGenerateMedia(principal, params);
       case "fs.list":
+      case "fs_list":
         return await toolFsList(principal, params);
       case "fs.tree":
       case "fs_tree":
         return await toolFsTree(principal, params);
       case "fs.delete":
+      case "fs_delete":
         return await toolFsDelete(principal, params);
       case "fs.glob":
+      case "fs_glob":
         return await toolFsGlob(principal, params);
       case "fs.grep":
+      case "fs_grep":
         return await toolFsGrep(principal, params);
 
       // The Gemini tool-name "dev_server_list" maps to dotted action