feat: Complete Spanish, French, Portuguese, Chinese localization and add German/Italian support

- Updated all Spanish (es) translation files with comprehensive translations for tracking, AI, family, insights, children, and settings pages
- Updated French (fr), Portuguese (pt), and Chinese (zh) translations to match English structure
- Added German (de) and Italian (it) language support with complete translation files
- Fixed medicine tracker route from /track/medication to /track/medicine
- Updated i18n config to support 7 languages: en, es, fr, pt, zh, de, it
- All tracking pages now fully localized: sleep, feeding, diaper, medicine, activity
- AI assistant interface fully translated with thinking messages and suggested questions
- Family management and insights pages now support all languages

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

maternal-web/locales/zh/common.json

@@ -33,7 +33,7 @@
   "home": "首页",
   "settings": "设置",
   "profile": "个人资料",
-  "logout": "退出",
+  "logout": "退出登录",
   "login": "登录",
   "signup": "注册",
   "email": "邮箱",
@@ -44,7 +44,7 @@
   "duration": "持续时间",
   "notes": "备注",
   "optional": "可选",
-  "required": "必填",
+  "required": "必需",
   "units": {
     "metric": "公制",
     "imperial": "英制"
@@ -52,28 +52,28 @@
   "measurements": {
     "weight": "体重",
     "height": "身高",
-    "temperature": "温度",
+    "temperature": "体温",
     "volume": "容量"
   },
   "navigation": {
     "home": "首页",
     "dashboard": "仪表板",
-    "tracking": "追踪",
-    "trackActivity": "记录活动",
-    "track": "记录",
+    "tracking": "跟踪",
+    "trackActivity": "跟踪活动",
+    "track": "跟踪",
     "ai": "AI助手",
     "aiChat": "AI聊天",
     "family": "家庭",
-    "insights": "分析",
-    "children": "儿童",
+    "insights": "洞察",
+    "children": "孩子",
     "settings": "设置",
     "logout": "退出登录"
   },
   "connection": {
-    "syncActive": "实时同步活动",
+    "syncActive": "实时同步活跃",
     "syncDisconnected": "实时同步已断开",
-    "live": "在线",
+    "live": "实时",
     "offline": "离线",
-    "familyMembersOnline": "{{count}}位家庭成员在线"
+    "familyMembersOnline": "{{count}}个家庭成员在线"
   }
-}
+}