[Due for payment 2026-05-11] Extract WhisperBanner and SearchActionHeader from PureReportActionItem

[cristipaval]

Problem

The "Only visible to..." whisper banner and the search action header are inlined in PureReportActionItem, causing their hooks and computations to run for every action cell — even when not needed.

Proposed fix

Extract WhisperBanner and SearchActionHeader as self-gating components that only mount (and subscribe) when isWhisper === true or isOnSearch === true respectively.

Draft PR: #89169

Issue Owner

Current Issue Owner: @hungvu193

[LukasMod]

ready for review

[melvin-bot]

Reviewing label has been removed, please complete the "BugZero Checklist".