[diffs/edit] feat: add decorations API

[ije]

Decorations anchor arbitrary UI to a zero-based document position. Supply typed metadata with each decoration, then map it to an HTMLElement with the renderDecoration editor option. The editor owns positioning while your renderer owns the returned element.

import { Editor } from '@pierre/diffs/edit';

interface CursorMetadata {
  name: string;
  color: string;
}

const editor = new Editor<undefined, CursorMetadata>({
  renderDecoration({ metadata }) {
    const cursor = document.createElement('span');
    cursor.ariaLabel = `${metadata.name}'s cursor`;
    cursor.style.cssText = `display:block;width:2px;height:1lh;background:${metadata.color}`;
    return cursor;
  },
  onAttach(editor) {
    editor.setDecorations([
      {
        position: { line: 5, character: 26 },
        metadata: { name: 'Ada', color: '#7c3aed' },
      },
    ]);
  },
});

editor.edit(fileInstance);

// Each call replaces every decoration. Pass an empty array to clear them.
editor.setDecorations([]);

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Project	Deployment	Actions	Updated (UTC)
pierre-docs-diffs	Ready	Preview	Aug 6, 2026 5:15pm
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[ije]

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