fix(sdk): pickupItem no longer reports success when someone else wins the item

The wait predicate treated the ground publication disappearing as
completion, then returned success (and handed back any inventory item of
that id the bot already carried) even when the calling account gained
nothing - exactly the trap chopTree already guards against. Contested
fleet loot had to diff exact item counts around every call to know who won
(bug report 2026-08-10).

Success is now gaining the item, tracked by exact id count around the
pickup; ground disappearance only stops the wait. A short grace covers the
inventory add landing a tick after the ground removal. Losing the race
returns a new 'taken_by_other' reason.

Verified live on the local engine: drop + re-pickup still reports success
with the gained item.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

sdk/API.md

@@ -573,7 +573,7 @@ interface PickupResult {
   success: boolean;
   item?: InventoryItem;
   message: string;
-  reason?: 'item_not_found' | 'cant_reach' | 'inventory_full' | 'timeout';
+  reason?: 'item_not_found' | 'cant_reach' | 'inventory_full' | 'taken_by_other' | 'timeout';
 }
 ```
 

sdk/actions.ts

@@ -791,8 +791,6 @@ export class BotActions {
             return { success: false, message: 'Item not found on ground', reason: 'item_not_found' };
         }
 
-        const invCountBefore = this.sdk.getInventory().length;
-
         // Walk close to the item first (server handles final positioning via sendPickup)
         if (item.distance > 2) {
             const walkResult = await this.walkTo(item.x, item.z, 2);
@@ -814,8 +812,10 @@ export class BotActions {
             return { success: false, message: result.message };
         }
 
-        // Track total inventory item count (handles stackables)
-        const invTotalBefore = this.sdk.getInventory().reduce((sum, i) => sum + i.count, 0);
+        // Success is *gaining* the item, tracked by its exact id. The ground
+        // publication also disappears when another player wins the pickup, so
+        // disappearance alone only stops the wait - see chopTree.
+        const countBefore = countItems(this.sdk.getInventory(), item.id);
 
         try {
             const finalState = await this.sdk.waitForCondition(state => {
@@ -831,15 +831,10 @@ export class BotActions {
                         }
                     }
                 }
+                if (countItems(state.inventory, item.id) > countBefore) return true;
                 // Item disappeared from ground (picked up by us or someone else)
                 const stillOnGround = state.groundItems.some(g => g.x === item.x && g.z === item.z && g.id === item.id);
-                if (!stillOnGround) return true;
-                // New inventory slot appeared (non-stackable)
-                if (state.inventory.length > invCountBefore) return true;
-                // Existing stack grew (stackable)
-                const invTotalNow = state.inventory.reduce((sum, i) => sum + i.count, 0);
-                if (invTotalNow > invTotalBefore) return true;
-                return false;
+                return !stillOnGround;
             }, 10000);
 
             // Check for failure reasons
@@ -855,6 +850,20 @@ export class BotActions {
                 }
             }
 
+            // The ground removal can publish a tick before the inventory add
+            // lands - give the add a short grace before ruling it lost.
+            let gained = countItems(finalState.inventory, item.id) - countBefore;
+            if (gained <= 0) {
+                try {
+                    const settled = await this.sdk.waitForCondition(
+                        s => countItems(s.inventory, item.id) > countBefore, 1500);
+                    gained = countItems(settled.inventory, item.id) - countBefore;
+                } catch { /* no gain observed */ }
+            }
+            if (gained <= 0) {
+                return { success: false, message: `${item.name} was taken by someone else`, reason: 'taken_by_other' };
+            }
+
             const pickedUp = this.sdk.getInventory().find(i => i.id === item.id);
 
             // Wait one tick after picking up

sdk/types.ts

@@ -680,7 +680,7 @@ export interface PickupResult {
     success: boolean;
     item?: InventoryItem;
     message: string;
-    reason?: 'item_not_found' | 'cant_reach' | 'inventory_full' | 'timeout';
+    reason?: 'item_not_found' | 'cant_reach' | 'inventory_full' | 'taken_by_other' | 'timeout';
 }
 
 export interface DropItemResult {