Reworked per the Codex gate finding: the first approach widened the client
import predicate, which (a) conflicted with #3603's intentional _isExternalSession
gate and (b) let import_cli persist the subagent child as a WRITABLE, CLI-classified
session that then passed the poll-skip/active-refresh gates.
Corrected to a server-side, view-only recovery:
- api/routes.py: mark source='subagent' as NON-claimable in _is_claimable_cli_source
(both cli_meta and state.db source denylists). A subagent child now resolves via
the not_claimable branch -> read-only Session with its state.db transcript, and
build_session takes is_cli_flag (False for subagent children) so the recovered
session is NOT CLI-classified and can't widen the frontend _isExternalSession gates.
- static/sessions.js: REVERTED to master (no client change needed; #3603 contract intact).
- tests: assert reason=not_claimable, read_only=True, is_cli_session!=True, transcript present;
#2782 deleted-webui 404 preserved; #3603 _isExternalSession contract preserved.
58 tests green (5307 + 3603 + claim-cli + core-data-loss). Fixes#5307