Select the nearest reachable local depot

[adrunkhuman]

Summary

• Treat empty gameplay-mode environment values as normal runtime instead of enabling the fixed Rookgaard fixture route.
• Discover loaded depot lockers inside the bot current-position planning bubble, rank standable approaches deterministically, and preserve the selected locker actual depot ID.
• Validate at most two routes per scheduler turn, transfer the accepted plan into navigation, rebuild after displacement, and bound transient failures with timed suppression and 1/2/4-second retries.
• Record candidate counts, selected locker and approach, pathfinding evidence, retry outcomes, and failed navigation destinations.

Verification

• pwsh -File scripts/test-playerbot-gameplay.ps1 -Depot -Focused -SkipBuild - passed all eight real-depot, movement, and restart scenarios
• pwsh -File scripts/test-playerbot-gameplay.ps1 -FullNavigation -CorpseLoot -SpellTraining -MainlandLoop -Focused -SkipBuild - passed navigation, looting, trainer routing, and repeated mainland-loop regressions
• Normal stack with PLAYERBOT_HUNT_DURATION_SECONDS=1800 selected locker (32352,32225,7), stood at (32352,32226,7), opened and deposited normally, then started an 1,800-second hunt and fought for more than seven minutes without a terminal event

Related Issues

This restores the real-depot behavior accepted by #78 and the sustainable loop in #22. It contributes bounded map-derived locality behavior to #28 and removes a blocker from the level 8-20 benchmark in #93. It does not complete either open issue.

Limits

Unavailable and suppression timing are covered by production policy helpers rather than a long wall-clock failure scenario. The normal soak remains running for longer progression evidence.