fix(editor): make TextareaAutocomplete fully controlled to prevent update loops

[sentry]

What was changed

In apps/web/src/features/shared/textarea-autocomplete/index.tsx, removed the duplicated local value state and the useEffect that kept re-syncing props.value into it. TextareaAutocomplete is now fully controlled: it passes props.value ?? "" straight down to ReactTextareaAutocomplete and forwards change events via props.onChange without updating local state.

Why

TextareaAutocomplete maintained a local value mirror initialized from props.value, and ran:

useEffect(() => {
  setValue(props.value);
}, [props.value, value]);

Because the local value was included in the dependency array, any edit (e.g. typing or pasting an image, which dispatches a synthetic change event from insertOrReplace) called setValue(event.target.value) inside handleChange, immediately re-triggering the effect to write props.value back. In callers like /submit and the comment reply box—where the parent already holds controlled state (body / text)—the ping-pong between local state and the incoming prop produced back-to-back synchronous updates that exceeded React's maximum update depth (error #185).

Making the component purely controlled removes the redundant state copy and eliminates the update loop entirely.

Fixes ECENCY-NEXT-1GRK

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