feat: add Telegram push support with multi-target routes

Add a platform-aware route target system so a single route can forward
to several destinations at once (e.g. a Discord channel and a Telegram
group). Route.target becomes Route.targets[] with per-entry platform,
channelId/threadId for Discord and chatId/topicId for Telegram; the
legacy single-target format is normalized on load and accepted by the
admin API.

Implement the Telegram driver with HTML rendering and Bot API
sendMessage (chat_id + message_thread_id for topics, retry on 429/5xx),
plus /gh commands served over POST /telegram/webhook: login, logout,
comment, merge and close. The comment/merge/close commands resolve the
issue or PR from the replied-to notification message. OAuth binding now
stores a D1 telegram_links mapping and replies with a confirmation.

Sync the Telegram webhook from the scheduled trigger via setWebhook.

admin/composables/useI18n.ts

@@ -34,6 +34,8 @@ const en: Dict = {
   "route.noFilters": "no filters",
   "route.channel": "CHANNEL",
   "route.thread": "THREAD",
+  "route.chat": "CHAT",
+  "route.topic": "TOPIC",
   "route.fallback": "fallback",
   "filter.event": "Event",
   "filter.repo": "Repo",
@@ -64,13 +66,24 @@ const en: Dict = {
   "routeEditor.thread": "Thread ID",
   "routeEditor.threadNote": "(optional)",
   "routeEditor.threadPlaceholder": "Optional thread ID",
+  "routeEditor.platform": "Platform",
+  "routeEditor.chat": "Chat ID",
+  "routeEditor.chatPlaceholder": "Telegram group chat ID",
+  "routeEditor.topic": "Topic ID",
+  "routeEditor.topicNote": "(optional)",
+  "routeEditor.topicPlaceholder": "Optional topic (message_thread_id)",
+  "routeEditor.errChat": "Target {n} chat ID is required",
+  "routeEditor.targets": "Targets",
+  "routeEditor.targetsNote": "(one or more destinations)",
+  "routeEditor.addTarget": "+ Add target",
+  "routeEditor.errTargets": "Add at least one target",
   "routeEditor.cancel": "Cancel",
   "routeEditor.save": "Save route",
   "routeEditor.errFilterMatch": "Filter {n} needs a match value",
   "routeEditor.errAddFilter": "Add at least one filter",
   "routeEditor.errIdFormat": "ID must be a-z / 0-9 / dashes",
   "routeEditor.errName": "Name is required",
-  "routeEditor.errChannel": "Channel ID is required",
+  "routeEditor.errChannel": "Target {n} channel ID is required",
   "groupEditor.editTitle": "Edit group",
   "groupEditor.newTitle": "New group",
   "groupEditor.close": "Close",
@@ -161,6 +174,8 @@ const zh: Dict = {
   "route.noFilters": "无过滤器",
   "route.channel": "频道",
   "route.thread": "子区",
+  "route.chat": "群组",
+  "route.topic": "话题",
   "route.fallback": "兜底",
   "filter.event": "事件",
   "filter.repo": "仓库",
@@ -191,13 +206,24 @@ const zh: Dict = {
   "routeEditor.thread": "子区 ID",
   "routeEditor.threadNote": "（可选）",
   "routeEditor.threadPlaceholder": "可选的子区 ID",
+  "routeEditor.platform": "平台",
+  "routeEditor.chat": "群组 ID",
+  "routeEditor.chatPlaceholder": "Telegram 群组聊天 ID",
+  "routeEditor.topic": "话题 ID",
+  "routeEditor.topicNote": "（可选）",
+  "routeEditor.topicPlaceholder": "可选的话题 (message_thread_id)",
+  "routeEditor.errChat": "第 {n} 个目标群组 ID 为必填项",
+  "routeEditor.targets": "目标",
+  "routeEditor.targetsNote": "（一个或多个推送目标）",
+  "routeEditor.addTarget": "+ 添加目标",
+  "routeEditor.errTargets": "至少添加一个目标",
   "routeEditor.cancel": "取消",
   "routeEditor.save": "保存路由",
   "routeEditor.errFilterMatch": "第 {n} 个过滤器需要匹配值",
   "routeEditor.errAddFilter": "至少添加一个过滤器",
   "routeEditor.errIdFormat": "ID 只能是 a-z / 0-9 / 短横线",
   "routeEditor.errName": "名称为必填项",
-  "routeEditor.errChannel": "频道 ID 为必填项",
+  "routeEditor.errChannel": "第 {n} 个目标频道 ID 为必填项",
   "groupEditor.editTitle": "编辑分组",
   "groupEditor.newTitle": "新建分组",
   "groupEditor.close": "关闭",