Refactor CodeMirror hook to remove unsafe annotation access and align with official API

Title

Refactor CodeMirror hook to remove unsafe annotation access and align with official API

Description

In the current implementation of the CodeMirror hook, transaction annotations are accessed using a non-standard approach:

// @ts-expect-error
update?.transactions[0]?.annotations?.length === 1

This relies on bypassing TypeScript checks and accessing internal properties that are not part of the official CodeMirror API.

Problem

Uses @ts-expect-error, which hides type safety issues
Accesses non-typed/internal transaction properties
Not aligned with recommended CodeMirror patterns
Can lead to fragile or hard-to-maintain code
Proposed Solution

Refactor the implementation to use CodeMirror’s official Annotation API:

Define a custom annotation using Annotation.define
Attach the annotation during programmatic dispatch
Read it safely using transaction.annotation(...)

Example

const dispatchAnnotation = Annotation.define<boolean>();

view.dispatch({
  changes: { ... },
  annotations: dispatchAnnotation.of(true),
});

const isDispatch = transaction.annotation(dispatchAnnotation) === true;

Benefits

Removes the need for @ts-expect-error
Improves type safety
Aligns with CodeMirror best practices
Makes the code more maintainable and predictable

Locate the CodeMirror hook containing the transaction annotation access and inspect its programmatic dispatch path. Replace the internal transaction-property access with a defined CodeMirror annotation, then verify that dispatches attach it and transactions read it through the official annotation API without the TypeScript suppression.