useAutomationChat missing onUnmounted cleanup — watcher and async writes leak after teardown

[Chris0Jeky]

Summary

useAutomationChat registers a watch and fires async calls in onMounted but has no onUnmounted/onScopeDispose block. The watch stop handle is never stored or called. Async continuations can write to reactive state after component unmount.

Location

frontend/taskdeck-web/src/composables/useAutomationChat.ts, lines 331-344

Suggested Fix

Store the watch stop handle, call it in onScopeDispose, and add a mounted guard variable for async continuations.

Source

Found during codebase health analysis (2026-06-06).