feat(server): add pickup system for NPC stockpile material retrieval

NPCs can now retrieve crafting materials from stockpiles instead of
always gathering raw resources. The industry system checks if a
stockpile has needed materials before falling back to gathering.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/systems/industrySystem.ts

@@ -7,6 +7,7 @@ import type { GameMap } from '../map/GameMap.js';
 import type { GatheringState } from './gatheringSystem.js';
 import type { CraftingState } from './craftingSystem.js';
 import type { BuildingState, StructureData } from './buildingSystem.js';
+import type { PickupState } from './pickupSystem.js';
 import { RecipeRegistry } from '../industry/recipeRegistry.js';
 import { getEffectiveStat } from './statHelpers.js';
 import { industryConfig } from '../config/industryConfig.js';
@@ -56,6 +57,7 @@ export function industrySystem(world: World, map: GameMap): void {
     if (brain.currentGoal === 'gather' && world.getComponent<GatheringState>(entity, 'gatheringState')) continue;
     if (brain.currentGoal === 'gather' || brain.currentGoal === 'eat' || brain.currentGoal === 'rest') continue;
     if (brain.currentGoal === 'dropoff') continue;
+    if (brain.currentGoal === 'pickup') continue;
 
     const inv = world.getComponent<Map<string, number>>(entity, 'inventory')!;
     const pos = world.getComponent<Position>(entity, 'position')!;
@@ -114,6 +116,46 @@ export function industrySystem(world: World, map: GameMap): void {
     }
     if (didBuild) continue;
 
+    // Try pickup from stockpile for crafting
+    let didPickup = false;
+    const allCraftRecipes = registry.getAll().filter(r => !r.id.startsWith('build_'));
+    for (const recipe of allCraftRecipes) {
+      const neededItems: { itemId: string; quantity: number }[] = [];
+
+      for (const input of recipe.inputs) {
+        const haveInInv = inv.get(input.itemId) ?? 0;
+        const stillNeed = input.quantity - haveInInv;
+        if (stillNeed > 0) {
+          neededItems.push({ itemId: input.itemId, quantity: stillNeed });
+        }
+      }
+
+      if (neededItems.length === 0) continue; // NPC can already craft — handled above
+
+      // Find a stockpile that has all needed items
+      let stockpileEntity: number | null = null;
+      for (const sEntity of world.query('structure', 'position')) {
+        const sData = world.getComponent<StructureData>(sEntity, 'structure')!;
+        if (sData.type !== 'stockpile' || sData.buildProgress !== undefined) continue;
+        const hasAll = neededItems.every(n => (sData.inventory.get(n.itemId) ?? 0) >= n.quantity);
+        if (hasAll) {
+          stockpileEntity = sEntity;
+          break;
+        }
+      }
+
+      if (stockpileEntity !== null) {
+        brain.currentGoal = 'pickup';
+        world.addComponent<PickupState>(entity, 'pickupState', {
+          stockpileEntityId: stockpileEntity,
+          items: neededItems,
+        });
+        didPickup = true;
+        break;
+      }
+    }
+    if (didPickup) continue;
+
     // Fallback: gather
     brain.currentGoal = 'gather';
   }