Provider audit found 6 WorkProviders missing reachability gates before
returning jobs. Without them, pawns can be offered doomed walk-jobs
(target boxed in), JobRunner cancels each tick, Decision re-offers
same job → 20Hz busy-spin starves lower-priority work.
Fixed 4 here (mechanical pattern):
- PlantProvider._find_harvest: walkable-target check (mirrors _find_sow)
- SleepProvider: walkable bed-tile check
- ChopProvider: adjacent-walkable for impassable tree
- MineProvider: adjacent-walkable for impassable rock
Cooking/Crafting reachability changes (in the same audit's
recommendation) were attempted but caused intermittent null returns
that regressed cooking rate. Reverted those — they need more careful
work that doesn't break the existing flow. Filed separately.
Future cleanup: _find_adjacent_walkable duplicated across
ConstructionProvider, ChopProvider — extract to a base/util.
MCP-verified after revert: 2 meals + 1 bread + 2 grain in cabin crate
within 3700 ticks at ULTRA. Cooking fires, hauling fires, all
production paths operational.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>