Restore main's dropped onTerminalQueryReply mobile wiring (take-ours regression),
and split 3 files pushed over max-lines by the merge into cohesive named modules
(mobile-session-diff-line-row, host-client-context-contract,
orchestration-handler-test-harness). No max-lines disables or baseline bumps.
Co-authored-by: Orca <help@stably.ai>