feat(mcp): add streamable HTTP and stdio (#1911)

* feat(mcp): add streamable HTTP

alongside with frontend UI change, w/ support for stdio

* fix(mcp): address copilot reviews

* Update src/langbot/pkg/provider/tools/loaders/mcp.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix: resolve copilot reviews

* fix: Message -> MessageChunk

* feat: upgrade mcp module

* feat: add i18n

* feat(mcp): enhance MCPCardComponent with mode badge and reorder select items in MCPFormDialog

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: WangCham <651122857@qq.com>
Co-authored-by: Junyan Qin (Chin) <rockchinq@gmail.com>

web/src/i18n/locales/en-US.ts

@@ -467,8 +467,10 @@ const enUS = {
     getServerListError: 'Failed to get MCP server list: ',
     serverName: 'Server Name',
     serverMode: 'Connection Mode',
+    selectMode: 'Select Mode',
     stdio: 'Stdio Mode',
     sse: 'SSE Mode',
+    http: 'HTTP Mode',
     noServerInstalled: 'No MCP servers configured',
     serverNameRequired: 'Server name cannot be empty',
     commandRequired: 'Command cannot be empty',

web/src/i18n/locales/ja-JP.ts

@@ -474,6 +474,8 @@ const jaJP = {
     serverMode: '接続モード',
     stdio: 'Stdioモード',
     sse: 'SSEモード',
+    http: 'HTTPモード',
+    selectMode: '接続モードを選択',
     noServerInstalled: 'MCPサーバーが設定されていません',
     serverNameRequired: 'サーバー名は必須です',
     commandRequired: 'コマンドは必須です',

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

@@ -446,8 +446,10 @@ const zhHans = {
     getServerListError: '获取 MCP 服务器列表失败：',
     serverName: '服务器名称',
     serverMode: '连接模式',
+    selectMode: '选择模式',
     stdio: 'Stdio模式',
     sse: 'SSE模式',
+    http: 'HTTP模式',
     noServerInstalled: '暂未配置任何 MCP 服务器',
     serverNameRequired: '服务器名称不能为空',
     commandRequired: '命令不能为空',

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

@@ -445,6 +445,8 @@ const zhHant = {
     serverMode: '連接模式',
     stdio: 'Stdio模式',
     sse: 'SSE模式',
+    selectMode: '選擇連接模式',
+    http: 'HTTP模式',
     noServerInstalled: '暫未設定任何MCP伺服器',
     serverNameRequired: '伺服器名稱不能為空',
     commandRequired: '命令不能為空',