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/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',