feat: implement unified loading screens across various components

- Introduced a new UnifiedLoadingScreen component for consistent loading indicators in the application.
- Replaced existing loading implementations in LoginPage, AuthCallbackPage, DashboardLayout, and other components with the new unified loading screen.
- Updated translations for loading messages to enhance user experience and clarity.
- Improved loading states in the ElectricProvider and TokenHandler components to utilize the new loading screen, ensuring a cohesive look and feel during loading processes.

surfsense_web/messages/zh.json

@@ -3,6 +3,7 @@
 		"app_name": "SurfSense",
 		"welcome": "欢迎",
 		"loading": "加载中...",
+		"initializing": "正在初始化",
 		"save": "保存",
 		"cancel": "取消",
 		"delete": "删除",
@@ -76,9 +77,10 @@
 		"passwords_no_match": "密码不匹配",
 		"password_mismatch": "密码不匹配",
 		"passwords_no_match_desc": "您输入的密码不一致",
-		"creating_account": "正在创建您的账户...",
-		"creating_account_btn": "创建中...",
-		"redirecting_login": "正在跳转到登录页面..."
+		"creating_account": "正在创建您的账户",
+		"creating_account_btn": "创建中",
+		"redirecting_login": "正在跳转到登录页面",
+		"processing_authentication": "正在处理身份验证"
 	},
 	"searchSpace": {
 		"create_title": "创建搜索空间",
@@ -128,12 +130,15 @@
 		"api_keys": "API 密钥",
 		"profile": "个人资料",
 		"loading_dashboard": "正在加载仪表盘",
-		"checking_auth": "正在检查身份验证...",
+		"checking_auth": "正在检查身份验证",
 		"loading_config": "正在加载配置",
-		"checking_llm_prefs": "正在检查您的 LLM 偏好设置...",
+		"checking_llm_prefs": "正在检查您的 LLM 偏好设置",
+		"setting_up_ai": "正在设置 AI",
 		"config_error": "配置错误",
 		"failed_load_llm_config": "无法加载您的 LLM 配置",
 		"error_loading_chats": "加载对话失败",
+		"loading_chat": "正在加载对话",
+		"loading_document": "正在加载文档",
 		"no_recent_chats": "暂无最近对话",
 		"error_loading_space": "加载搜索空间失败",
 		"unknown_search_space": "未知搜索空间",
@@ -150,7 +155,7 @@
 		"create_search_space": "创建搜索空间",
 		"add_new_search_space": "添加新的搜索空间",
 		"loading": "加载中",
-		"fetching_spaces": "正在获取您的搜索空间...",
+		"fetching_spaces": "正在获取您的搜索空间",
 		"may_take_moment": "这可能需要一些时间",
 		"error": "错误",
 		"something_wrong": "出现错误",