Allow inline annotations on plans

Problem

When reviewing a generated plan, requesting changes requires restating the step and surrounding context in chat. This is verbose and error-prone.

Proposal

Allow users to select plan text or a plan step and attach an inline annotation. When submitted, annotations should be sent to the agent anchored to the exact plan location.

Desired UX

• Add comments directly to a line, selection, or step.
• Collect multiple annotations before requesting a revision.
• Preserve annotations across plan revisions, marking anchors stale when needed.
• Show which annotations were addressed and which remain unresolved.

Benefit

This would make plan iteration faster and more precise, without requiring users to retype context.

Comienza rastreando el flujo de revisión del plan generado y cómo se envían las solicitudes de revisión al agente. Identifica los puntos de entrada para seleccionar texto o pasos del plan, enviar varias anotaciones y renderizar planes revisados. La tarea estará completada cuando las anotaciones puedan anclarse, conservarse o marcarse como obsoletas entre revisiones, y mostrarse como resueltas o sin resolver.