test(sw): open the Firefox Overview check with &verification

The Overview selection controls are shown only with &verification since
the 2026-10-21 simplification; overview.browser.mjs already used it, so
the Firefox suite stopped before its popup checks. Now 9/9 PASS.

packages/sw/tests/overview-firefox.browser.mjs

@@ -12,7 +12,8 @@ const sleep = ms => new Promise(resolve=>setTimeout(resolve,ms))
 const root=path.resolve('storybook-static'),mime={'.html':'text/html','.js':'text/javascript','.css':'text/css','.json':'application/json','.svg':'image/svg+xml','.ttf':'font/ttf','.png':'image/png'}
 const server=http.createServer(async(req,res)=>{try{const p=new URL(req.url,'http://localhost').pathname,file=path.resolve(root,'.'+decodeURIComponent(p==='/'?'/index.html':p));if(path.relative(root,file).startsWith('..'))return res.writeHead(403).end();res.setHeader('Content-Type',mime[path.extname(file)]??'application/octet-stream');res.end(await readFile(file))}catch{res.writeHead(404).end()}})
 await new Promise(resolve=>server.listen(0,'127.0.0.1',resolve))
-const url=`http://127.0.0.1:${server.address().port}/iframe.html?id=sw-header--overview&viewMode=story`
+// &verification shows the Overview's selection controls (hidden by default since the 2026-10-21 simplification), as in overview.browser.mjs.
+const url=`http://127.0.0.1:${server.address().port}/iframe.html?id=sw-header--overview&viewMode=story&verification`
 let processFirefox,ws
 try {
   for(const [width,height]of[[1400,1000],[500,800]]){