XY-705: Lane control P2: add agent guidance for controlled recovery after interrupt or steer

[yvette-carlisle]

Summary

• add a lane-control recovery runbook for post-interrupt, hard fallback, broad steer, task replacement, and ambiguous evidence paths
• tighten Decodex automation and manual CLI skills with inspect/resume/scan/label/manual-attention decision trees
• route docs from the index and lane-control spec so capability stays separate from recovery procedure

Verification

• semantic drift helper: no stale phrase hits; agent verdict pass against CLI/API source anchors
• cargo make fmt
• cargo make lint-fix
• cargo make test (937 passed, 1 skipped)