feat: add player resource node harvesting

simulation/SimulationManager.gd

@@ -208,24 +208,40 @@ func notify_npc_navigation_failed(npc_id: int) -> void:
 func notify_npc_target_unavailable(npc_id: int) -> void:
 	notify_npc_navigation_failed(npc_id)
 
+func harvest_resource_node(node: ResourceNode) -> float:
+	if node == null or not node.can_player_use:
+		return 0.0
+
+	var extracted := node.extract()
+	if extracted <= 0.0:
+		return 0.0
+
+	village.apply_resource_delta(node.resource_id, extracted)
+	village_changed.emit(village)
+
+	if DEBUG_LOGS:
+		print("[SimulationManager] Player extracted ", extracted, " ", node.resource_id, " from ", node.node_id)
+
+	return extracted
+
 func eat_food(amount: float) -> void:
-	village.food -= amount
+	village.apply_resource_delta(&"food", -amount)
 	village_changed.emit(village)
 		
 func add_food(amount: float) -> void:
-	village.food += amount
+	village.apply_resource_delta(&"food", amount)
 	village_changed.emit(village)
 
 func add_wood(amount: float) -> void:
-	village.wood += amount
+	village.apply_resource_delta(&"wood", amount)
 	village_changed.emit(village)
 
 func add_safety(amount: float) -> void:
-	village.safety = clamp(village.safety + amount, 0.0, 100.0)
+	village.apply_resource_delta(&"safety", amount)
 	village_changed.emit(village)
 
 func add_knowledge(amount: float) -> void:
-	village.knowledge += amount
+	village.apply_resource_delta(&"knowledge", amount)
 	village_changed.emit(village)
 	
 func get_starving_count() -> int: