Feat/space cta optimization (#2089)

* feat(wizard): persist wizard progress to backend for session resumption

Store wizard step, selected adapter, created bot UUID, and runner
selection in the metadata table. On revisit, the wizard restores
progress and verifies the bot still exists. Progress is cleared
automatically when the wizard is completed or skipped.

* feat(dynamic-form): optimize LLM model selection with space login CTA and improve localization strings

* feat(web): add LangBot Cloud CTA for webhook URL fields in community edition

Show a subtle hint below webhook URL fields prompting users about
LangBot Cloud's public endpoint, only visible in community edition.
Covers all 8 webhook-based adapters with i18n support (4 locales).

web/src/i18n/locales/zh-Hans.ts

@@ -222,6 +222,10 @@ const zhHans = {
     loginWithSpace: '通过 Space 登录',
     loginToUseModels: '通过 Space 登录以使用云端模型',
     noModels: '暂无模型',
+    langbotModels: 'LangBot 模型',
+    spaceTrialTooltip:
+      '免费试用积分已就绪！通过 Space 登录即可零配置使用云端模型。',
+    unlockModels: '登录以使用',
     editProvider: '编辑供应商',
     addProvider: '添加供应商',
     addProviderHint: '添加自定义供应商以使用其他来源的模型',
@@ -299,6 +303,9 @@ const zhHans = {
     webhookUrlHint:
       '点击输入框自动全选，然后按 Ctrl+C (Mac: Cmd+C) 复制，或点击右侧按钮',
     webhookUrlHintEither: '以上两个地址任选其一填入平台配置即可',
+    webhookSaasHint:
+      'Webhook 需要公网可访问的域名。LangBot Cloud 为你的机器人提供开箱即用的公网地址。',
+    webhookSaasLink: '了解 LangBot Cloud',
     logLevel: '日志级别',
     allLevels: '全部级别',
     selectLevel: '选择级别',