Harden Chrome bridge framing and preserve panel state for IDE beta 7

apps/desktop/electron/chrome-bridge.mjs

@@ -223,7 +223,7 @@ export async function startChromeBridge({ directory, resolveBackend }) {
         let message
         try { message = JSON.parse(line) } catch { socket.destroy(); return }
         if (!authenticated) {
-          if (typeof message.token !== 'string' || message.token.length !== token.length ||
+          if (!message || typeof message.token !== 'string' || !/^[a-f0-9]{64}$/.test(message.token) ||
               !timingSafeEqual(Buffer.from(message.token), Buffer.from(token))) { socket.destroy(); return }
           authenticated = true
           clearTimeout(timer)
@@ -245,8 +245,13 @@ export async function startChromeBridge({ directory, resolveBackend }) {
     server.listen(`\\\\.\\pipe\\${pipe}`, resolve)
   })
   const temporary = `${discovery}.${process.pid}.tmp`
-  await writeFile(temporary, JSON.stringify({ protocol: 1, pipe, token }), { mode: 0o600 })
-  await rename(temporary, discovery)
+  try {
+    await writeFile(temporary, JSON.stringify({ protocol: 1, pipe, token }), { mode: 0o600 })
+    await rename(temporary, discovery)
+  } catch (error) {
+    server.close()
+    throw error
+  }
   return async () => {
     for (const socket of sockets) socket.destroy()
     server.close()