test: isolate runtime ownership stubs

deploy/runtime-start.test.ts

@@ -75,7 +75,7 @@ fi
 exec /usr/bin/id "$@"
 `;
 
-const chownStub = `#!/bin/sh
+const ownershipStub = `#!/bin/sh
 exit 0
 `;
 
@@ -135,7 +135,9 @@ describe('container runtime startup', () => {
       ),
       writeFile(join(temporaryRoot, 'gosu'), gosuStub, { mode: 0o755 }),
       writeFile(join(temporaryRoot, 'id'), idStub, { mode: 0o755 }),
-      writeFile(join(temporaryRoot, 'chown'), chownStub, { mode: 0o755 }),
+      writeFile(join(temporaryRoot, 'chgrp'), ownershipStub, { mode: 0o755 }),
+      writeFile(join(temporaryRoot, 'chmod'), ownershipStub, { mode: 0o755 }),
+      writeFile(join(temporaryRoot, 'chown'), ownershipStub, { mode: 0o755 }),
       writeExport(appExport, [
         { key: 'APP_ORIGIN', value: 'https://exported.invalid' },
         { key: 'DISCORD_CLIENT_ID', value: 'exported-discord-client' },