ed22b31959e2dc2e979254cd21ddb972fc0bda7b  [Site Isolation] Services, paste, and Genmoji insertion don't work with a selection in a cross-origin iframe

Classified as not security-relevant.
Triage note: Replaces protect(legacyMainFrameProcess())->send/sendSync with sendToFocusedOrMainFrameProcess / sendSyncToProcessContainingFrame for pasteboard reads/writes and threads frameID into grantAccessToCurrentPasteboardData so the focused frame's process (possibly cross-origin under site isolation) gets access. Site-isolation routing plumbing; an access-control refinement but no identified exploitable bug.
This commit was flagged by the signal scorer and reviewed by AI (not a human). It is listed only so the triage is auditable; there is no root-cause analysis because this is not a vulnerability fix.

Structural signals: smartptr_member_added (+4.87), surgical (+1.3)