Source: task/getroot-comment-tree-scope (plan/steward-linker-design) — getRoot's union querySelector resolved to <main> on new reddit, so the shadow-piercing walk over-collected reddit chrome.
- getRoot now tries shreddit-comment-tree, then .commentarea, then main/body sequentially (narrow-first) instead of one union querySelector, so the comment tree wins when present.
- collectInto takes an allowShadow flag: a narrow comment root pierces every open shadow host; a broad fallback root descends only into comment-component hosts (tagName SHREDDIT-COMMENT*), so chrome shadow roots (nav/sidebar/composer) are never walked.
- README + AGENTS shadow-DOM notes updated to describe the two-layer scoping.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>