End-to-end through the real endpoint+service stack (only the AI boundary mocked:
match_or_build outcome + ai_tree_builder.generate_next_node). Asserts the captured
FlowProposal is outcome-validated with l1_session_id set / source_session_id null
and tree root 'n1' (meta entry skipped); and that escalate notifies the account's
engineers and the session surfaces in GET /l1/escalations. 2 passed.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
