Append RETIRED blocks to CON-tab-capture-binding and
CON-service-worker-keepalive (the two SPEC-derived constraints that are
no longer valid under getDisplayMedia + port-keepalive). Add new
CON-display-capture-binding consolidating the replacement contract.
Originals stay intact for provenance; RETIRED is appended below each.
Append Amendment blocks to DEC-003 (getDisplayMedia replaces tabCapture)
and DEC-010 (long-lived port replaces alarms keepalive) so downstream
phases see the new API contract. Original text intact; amendments are
appended, not replacements. Maintains intel/* provenance for the
Phase 01 doc cascade.
