split CookingProvider out of CraftingProvider — fixes starvation

Player report: pawns starve even with harvested crops because cooking
never happens. Root cause: CraftingProvider handled both crafting-skill
and cooking-skill bills with priority 4, below Plant=5 and Chop=5 in
Decision's tiebreaker. Pawns endlessly harvested + chopped instead of
cooking the food already on the floor; raw +25 vegetable couldn't
outpace HUNGER_DECAY × 3 pawns.

CraftingProvider now filters bills to required_skill == &"crafting"
only. New CookingProvider (category=&"cooking", priority=6) handles
required_skill == &"cooking" bills (bread, meal_from_vegetables) with
identical find/score logic including the ingredient2 buffer flow.

pawn.work_priorities default now includes &"cooking": 3 (matches the
9-category design spec). decision.gd category-list comment updated.
WorkPriorityMatrix gains a "Cook" column.

MCP runtime verified: pawns now decide `cooking(pri=3) → Craft Veggie
meal at Hearth` immediately after vegetables exist; 2 bread items
appeared by tick 261 of a fresh boot.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scenes/ui/work_priority_matrix.gd

@@ -21,10 +21,11 @@ class_name WorkPriorityMatrix extends CanvasLayer
 ## round-trips pawn.work_priorities (via pawn.to_dict) will reflect correctly.
 
 const CATEGORIES: Array[StringName] = [
-	&"construction", &"chop", &"plant", &"mine", &"crafting", &"haul", &"clean", &"doctor"
+	&"construction", &"cooking", &"chop", &"plant", &"mine", &"crafting", &"haul", &"clean", &"doctor"
 ]
 const CATEGORY_LABELS: Dictionary = {
 	&"construction": "Build",
+	&"cooking":      "Cook",
 	&"chop":         "Chop",
 	&"plant":        "Plant",
 	&"mine":         "Mine",