ba88febc77
The disabled-state effect calls editor.setEditable, which triggers a
ProseMirror transaction → onUpdate → bind:value/mentionedPersons writes →
host re-render → child prop pass-through → effect re-fires. Without an
idempotence check, this exceeds Svelte's effect_update_depth and crashes
every consuming spec (TranscriptionBlock 22/22). Compare editor.isEditable
against the desired value first; only call setEditable when it actually
needs to change.
Follow-up to 6ef888a1.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>