Some injected UI (browser-extension debug panels, web components) renders into a
CLOSED shadow root that eval/innerText cannot read. --pierce walks the CDP DOM
tree (DOM.getDocument depth:-1 pierce:true), which includes closed shadow roots
and child documents, and collects text nodes (skipping script/style/etc).
Review-safe: rides the per-tab debugger session already attached, no new Chrome
permission and no ab-connect/extension change — so it works in extension-relay
mode without touching the published extension. Verified live: a closed-shadow
panel that main-world eval reports HIDDEN is read in full via --pierce.
First slice of #30 (read extension/injected-panel content). Deeper extension
introspection (background SW / chrome.storage) stays a launch-mode / raw-CDP
concern, deliberately NOT done by expanding ab-connect's debugger powers.
leeguooooo
af8823b27b