Fix date handling in CollectionModal to set null values for missing start and end dates; update localization files to add new confirmation messages and labels.

frontend/src/locales/zh.json

@@ -197,7 +197,25 @@
     "show": "展示",
     "download_calendar": "下载日历",
     "md_instructions": "在这里写下你的标记...",
-    "preview": "预览"
+    "preview": "预览",
+    "checklist_delete_confirm": "您确定要删除此清单吗？\n此操作无法撤消。",
+    "clear_location": "明确的位置",
+    "date_information": "日期信息",
+    "delete_checklist": "删除清单",
+    "delete_note": "删除注释",
+    "delete_transportation": "删除交通",
+    "end": "结尾",
+    "ending_airport": "结束机场",
+    "flight_information": "航班信息",
+    "from": "从",
+    "no_location_found": "没有找到位置",
+    "note_delete_confirm": "您确定要删除此注释吗？\n此操作无法撤消。",
+    "out_of_range": "不在行程日期范围内",
+    "show_region_labels": "显示区域标签",
+    "start": "开始",
+    "starting_airport": "出发机场",
+    "to": "到",
+    "transportation_delete_confirm": "您确定要删除此交通工具吗？\n此操作无法撤消。"
   },
   "home": {
     "desc_1": "轻松发现、规划和探索",
@@ -364,7 +382,9 @@
     "item_cannot_be_empty": "项目不能为空",
     "items": "项目",
     "new_item": "新商品",
-    "save": "节省"
+    "save": "节省",
+    "checklist_viewer": "清单查看器",
+    "new_checklist": "新清单"
   },
   "collection": {
     "collection_created": "收藏创建成功！",
@@ -373,7 +393,8 @@
     "edit_collection": "编辑收藏",
     "error_creating_collection": "创建集合时出错",
     "error_editing_collection": "编辑集合时出错",
-    "new_collection": "新系列"
+    "new_collection": "新系列",
+    "public_collection": "公共收藏"
   },
   "notes": {
     "add_a_link": "添加链接",
@@ -386,7 +407,8 @@
     "note_public": "该笔记是公开的，因为它属于公共收藏。",
     "open": "打开",
     "save": "节省",
-    "invalid_url": "无效网址"
+    "invalid_url": "无效网址",
+    "note_viewer": "笔记查看器"
   },
   "transportation": {
     "date_and_time": "日期",