docs(adr): ADR-0138 D2 gains class 6, the acl public_read file download; the G2 result recorded (still Proposed)

Record revision under the G2 ruling (letter A): D2's closed list names the
ADR-0104 opt-in file download as a sixth door class, with its admission,
what it runs as and its enforcer. Every count of the door classes, the
adoption rule, the enforcement map, acceptance criterion 2, the quoted
ADR-0056 back-pointer text and E2 follow. The G2 sweep's class-level
result is recorded: classes 1 to 5 match, the everything-else class does
not (three families, named at function level), and acceptance waits on
their three defect cards and a re-measurement. Status stays Proposed.

Claude-Session: https://claude.ai/code/session_01VZqqwTj2wsihZEbfT6yyYN
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude