- flow-proposal.ts: source_session_id nullable + add l1_session_id (matches backend
FlowProposalSummary).
- ProposalDetail.tsx: render an 'AI L1 walk (outcome-validated)' note when
l1_session_id is set instead of the /pilot/{source_session_id} link; fall back to
the link for ai_session-sourced proposals.
- New L1EscalationsSection.tsx (GET /l1/escalations) — expandable rows with walked-path
summary; renders nothing if empty. Mounted below the FlowPilot queue on
EscalationQueuePage. tsc -b + eslint clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>