feat: remove legacy alert rules, superseded by automations

Alert rules already auto-migrate into automations on boot and the old
engine stands down after. Deletes the rule/firing tables, routes, UI,
and AI tools; keeps notification channels since automations still use
them. Also fixes automations' notify step, which still called the
deleted repository.

src/ui/locales/translated/zh_TW.json

@@ -287,7 +287,6 @@
     "loading": "載入中...",
     "noData": "無可用資料",
     "allClear": "一切正常",
-    "acknowledgeAlert": "確認",
     "noPingUrls": "未設定 URL",
     "pingLabel": "標籤",
     "addPingUrl": "新增 URL",
@@ -324,8 +323,6 @@
     "widgetMetricsChartDesc": "主機的歷史 CPU、記憶體、磁碟或網路圖表",
     "widgetHostGridName": "主機方格",
     "widgetHostGridDesc": "SSH 主機狀態的方格檢視",
-    "widgetAlertFeedName": "警報動態",
-    "widgetAlertFeedDesc": "即時警報觸發並支援確認",
     "widgetPingStatusName": "Ping 狀態",
     "widgetPingStatusDesc": "一個或多個 URL 的 HTTP ping 狀態",
     "widgetRecentActivityName": "近期活動",
@@ -747,7 +744,6 @@
     "portForwarding": "轉發",
     "sftp": "SFTP",
     "connections": "連線",
-    "alerts": "警示",
     "serial": "序列",
     "keepSideMenuOpen": "保持菜單打開",
     "collapseSideMenu": "折疊菜單",
@@ -4890,21 +4886,6 @@
     "viewHistory": "檢視歷史記錄"
   },
   "alerts": {
-    "tabFirings": "警示",
-    "tabRules": "規則",
-    "tabChannels": "通道",
-    "noFirings": "沒有未確認的警示",
-    "noRules": "未設定警示規則",
-    "noChannels": "未設定通知通道",
-    "rulesDesc": "警示規則會觸發通知",
-    "channelsDesc": "警示通知傳送的位置",
-    "acknowledge": "確認",
-    "ackAll": "全部確認",
-    "allAcknowledged": "所有警示已確認",
-    "ackFailed": "確認警示失敗",
-    "ackAllFailed": "確認所有警示失敗",
-    "showAcknowledged": "顯示全部",
-    "hideAcknowledged": "隱藏已確認",
     "addChannel": "新增通道",
     "editChannel": "編輯通道",
     "channelName": "名稱",
@@ -4917,22 +4898,7 @@
     "ntfyTopic": "主題",
     "ntfyTopicRequired": "主題為必填",
     "ntfyToken": "存取權杖（選填）",
-    "channelSaveFailed": "無法儲存頻道",
-    "test": "測試",
-    "testSent": "已傳送測試通知",
-    "testFailed": "測試通知失敗",
-    "testFailedWithReason": "測試通知失敗： {{reason}}",
-    "addRule": "新增警示規則",
-    "editRule": "編輯警示規則",
-    "ruleName": "規則名稱",
-    "ruleNameRequired": "名稱為必填",
-    "triggerType": "觸發條件",
-    "thresholdValue": "閾值（%）",
-    "durationSeconds": "持續時間（秒，0 = 立即觸發）",
-    "cooldownMinutes": "冷卻時間（分鐘）",
-    "channels": "通知頻道",
-    "noChannelsHint": "請先於「頻道」分頁新增頻道",
-    "ruleSaveFailed": "無法儲存規則"
+    "channelSaveFailed": "無法儲存頻道"
   },
   "ai": {
     "title": "助理",