Let stuck bots fight adjacent attackers without chasing

[adrunkhuman]

• Let stalled bots fight one adjacent attacker without chasing or requiring navigation to prove that killing it opens a route. Share failed-movement observations across patrol, service, depot, and NPC travel.
• Prefer an attacker on the intended step, otherwise the easiest survivable fight. Retain the target across replans; release when the intended passage opens, the target dies or leaves reach, safety changes, or the workflow is interrupted.
• Replace timed transit defense and breakout escalation with movement-failure state. Preserve navigation budgets, healing priority, and the independent 20-second corpse-loot deadline.
• Add fallback cause, intended-step, and fight-estimate telemetry, plus contracts for target retention and release.

This deliberately permits combat that may not resolve the route. It requires an active adjacent attacker and estimated survivability; passive blockers and genuinely unreachable destinations can still prevent progress. General unattended reliability is not established.