Replaces the task-lane SuggestedFix card with the ProposalBanner docked
above the chat composer. Wires:
- Resolve-while-verifying auto-marks applied_success (one-click resolve).
- Escalate-while-verifying opens EscalateInterceptDialog to capture the
real outcome (default: didn't work) before handoff.
- 3+ post-apply engineer messages trigger the passive Nudge banner.
- AI [FIX_OUTCOME] proposals surface in the AIConfirming state; one-click
confirm applies the outcome.
Banner state resets on session switch via resetSessionDerivedState.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>