feat: handle inventory_delta messages and broadcast to browsers

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

main.py

@@ -1979,6 +1979,33 @@ async def ws_receive_snapshots(
                 except Exception as e:
                     logger.error(f"Failed to process inventory for {data.get('character_name', 'unknown')}: {e}", exc_info=True)
                 continue
+            # --- Inventory delta: single item add/remove/update ---
+            if msg_type == "inventory_delta":
+                try:
+                    action = data.get("action")
+                    char_name = data.get("character_name", "unknown")
+
+                    if action == "remove":
+                        item_id = data.get("item_id")
+                        async with httpx.AsyncClient(timeout=10.0) as client:
+                            await client.delete(
+                                f"{INVENTORY_SERVICE_URL}/inventory/{char_name}/item/{item_id}"
+                            )
+                    elif action in ("add", "update"):
+                        item = data.get("item")
+                        if item:
+                            async with httpx.AsyncClient(timeout=10.0) as client:
+                                await client.post(
+                                    f"{INVENTORY_SERVICE_URL}/inventory/{char_name}/item",
+                                    json=item
+                                )
+
+                    # Broadcast delta to all browser clients
+                    await _broadcast_to_browser_clients(data)
+                    logger.debug(f"Inventory delta ({action}) for {char_name}")
+                except Exception as e:
+                    logger.error(f"Failed to process inventory delta: {e}", exc_info=True)
+                continue
             # --- Vitals message: store character health/stamina/mana and broadcast ---
             if msg_type == "vitals":
                 payload = data.copy()