Bug: pawns weren't replanting. _find_sow required a TYPE_GRAIN item
as seed, but Millstone's flour bill (FOREVER) consumed all grain
before sow could claim it. With CookingProvider now priority 6, grain
contention is fatal — TILLED crops sit forever.
Fix: removed the grain requirement. Sow is now Rimworld-style — the
designation triggers work; no input is consumed. _find_sow returns a
2-toil job (walk → interact). Crop.on_sow_tick just flips stage to
SOWN.
Feature: 4 new paint tools in BuildDrawer's new "Farm" section column
— TOOL_PAINT_CROP_WHEAT/POTATO/CORN/STRAWBERRY. Painting a grass
tile spawns a TILLED Crop entity that pawns then sow. World rejects
non-grass tiles, occupied tiles, and non-walkable terrain. 9 new
string keys, kind-specific thumbnail draws (gold/tan/yellow/red).
MCP verified: 12 forced-TILLED crops fully cycled TILLED → SOWN →
growth → READY within ~3000 ticks. Paint tool spawned wheat crop at
(35, 30); wall tile at (44, 23) correctly rejected.
Followup smell: cancelling a designation on a player-painted crop
will queue_free even if grown — Crop has no can_complete. Future
guard could skip crops past TILLED.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>