P9(4): remove local-core live-test trio — outbound speed test + egress probe, restart/stop xray endpoints

Per user decision 2026-10-21 (reverses the earlier keep call in
PANEL-LITE-SPEC.md, now amended): the lite panel never runs a local
core, so measuring/probing from the panel host is meaningless.

Backend:
- delete service/outbound probe implementation (probe_http.go and its
  tests) and the TestOutbound/TestOutbounds batch prober; outbound
  traffic accounting (AddTraffic/GetOutboundsTraffic/Reset) unchanged
- drop POST /panel/api/xray/testOutbound + testOutbounds routes and the
  outboundTestUrl setting (get/update plumbing removed; stored rows in
  existing DBs are inert)
- drop POST /panel/api/server/restartXrayService + stopXrayService
  routes/handlers and the node-sync allowlist entry; the service-level
  Stop/RestartXrayService stay for internal import/restore flows
- node-sync allowlist contract test updated to the new inventory

Frontend:
- remove test buttons/mode switch/test-all from outbounds tab, card
  list and table columns; delete TestResultPopover and CountryPill;
  drop the egress/country/latency columns fed by probe results
- remove outboundTestUrl state and save plumbing from useXraySetting
  and the Basics tab field; drop OutboundTestResult schemas
- delete the 15 now-dead i18n keys from all 13 locales (incl. the
  restart/stop keys orphaned since P6/P7 — i18n-dead-keys test green)
- tests: drop the test-URL hook test, re-probe the loopback index
  mapping through Move-to-top, regenerate API types (gen)

internal/web/translation/zh-TW.json

@@ -1172,10 +1172,6 @@
     },
     "xray": {
       "save": "儲存",
-      "restartSuccess": "Xray 已成功重新啟動",
-      "stopSuccess": "Xray 已成功停止",
-      "restartError": "重新啟動 Xray 時發生錯誤。",
-      "stopError": "停止 Xray 時發生錯誤。",
       "importRules": "匯入規則",
       "exportRules": "匯出規則",
       "importOutbounds": "匯入出站",
@@ -1206,8 +1202,6 @@
       "FreedomHappyEyeballsTryDelayDesc": "嘗試備用位址族之前等待的毫秒數。150–250 毫秒是不錯的起點。",
       "RoutingStrategy": "配置路由域策略",
       "RoutingStrategyDesc": "設定 DNS 解析的整體路由策略",
-      "outboundTestUrl": "出站測試 URL",
-      "outboundTestUrlDesc": "測試出站連線時使用的 URL",
       "Torrent": "遮蔽 BitTorrent 協議",
       "Inbounds": "入站",
       "Outbounds": "出站",
@@ -1355,18 +1349,9 @@
       },
       "outbound": {
         "tag": "標籤",
-        "egress": "出口",
-        "egressHint": "執行 HTTP 測試以顯示出口 IP 與所在國家／地區。",
         "outboundStatus": "出站狀態",
         "sendThrough": "傳送通過",
         "targetStrategy": "目標解析策略",
-        "modeRealDelay": "真實延遲",
-        "testModeTooltip": "TCP: 快速 dial-only 探測。HTTP: 透過 xray 的完整請求。真實延遲: 含建立連線的總耗時。",
-        "testAll": "全部測試",
-        "httpStatus": "HTTP 狀態",
-        "breakdownConnect": "代理連線",
-        "breakdownTls": "經由出站的 TLS",
-        "breakdownTtfb": "首位元組",
         "country": "國家",
         "server": "伺服器",
         "city": "城市",
@@ -1675,4 +1660,4 @@
     "noIpRecord": "❗ 沒有 IP 記錄！"
   },
   "email": {}
-}
+}