fix(snapshot): resolve DevTools selected element in take_snapshot output

[syf2211]

Summary

Fix take_snapshot so the element selected in the Chrome DevTools Elements panel is exposed with a stable uid and [selected in the DevTools Elements panel] marker.

Motivation

Fixes #2243. When users select an element in DevTools and ask an agent to inspect it, the snapshot reported that an element was selected but did not identify which one. This happened because:

1. selectedElementUid was resolved against the previous textSnapshot, not the snapshot being built.
2. Elements outside the accessibility tree were never inserted, even in verbose mode.

Changes

• Resolve selectedElementUid from the in-progress snapshot tree (idToNode).
• When the selected element is missing from the a11y tree, resolve it via adoptBackendNode and insert it with the existing insertExtraNodes path.
• Restore page.extraHandles after the temporary selected-element insertion to avoid leaking state across snapshots.
• Update the unresolved-selection note to stop recommending verbose mode (which does not fix this case).

Tests

• node scripts/test.mjs tests/TextSnapshot.test.ts tests/formatters/snapshotFormatter.test.ts — all pass
• npm run check-format — pass

Notes

• Selection inside iframes or closed shadow roots may still fail to resolve; the note now explains likely causes.
• Google CLA signature may be required for this repository.

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[syf2211]

I have read the CLA Document and I hereby sign the CLA

[syf2211]

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[syf2211]

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[syf2211]

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[nattallius]

Hi, thank you for you effort, but that issue has already been solved in #2295 . Closing as duplicate