feat: add backend autocomplete for suppliers and users in inbound

Co-authored-by: aider (openai/DeepSeek-V3.2-Thinking) <aider@aider.chat>

inventory-backend/app/services/inbound/product_service.py

@@ -350,4 +350,30 @@ class ProductInboundService:
             return {"total": pagination.total, "items": items}
         except:
             traceback.print_exc()
-            return {"total": 0, "items": []}
+            return {"total": 0, "items": []}
+
+    # ============================================================
+    # 7. 系统用户搜索
+    # ============================================================
+    @staticmethod
+    def search_system_users(keyword):
+        """搜索系统用户（活跃状态）"""
+        from app.models.system import SysUser
+        try:
+            query = SysUser.query.filter(SysUser.status == 'active')
+            if keyword:
+                kw = f'%{keyword}%'
+                query = query.filter(db.or_(
+                    SysUser.username.ilike(kw),
+                    SysUser.email.ilike(kw)
+                ))
+            query = query.order_by(SysUser.username)
+            users = []
+            for u in query.limit(20).all():
+                users.append({
+                    'value': u.username,
+                    'email': u.email
+                })
+            return users
+        except Exception:
+            return []