入站详情可以测常用 AI 服务的可访问性

判定按状态码白名单而不是只认 200：探测不带鉴权，OpenAI 回 401、Anthropic 回 405
才是正常应答，说明 TLS 握手、路由、目标服务全都正常。清单和白名单照 sub2api 的
代理质量检查抄来。

失败文案不照抄 Bun：本机端口没人监听时它给的是「Unable to connect. Is the
computer able to access the url?」，把矛头指向目标网址，而真正的原因在本机。

对话框留在 InboundDetail 而不是提到 RouterPage——它不写配置文件也不改内核状态，
不需要走那条 commit 链路。firstPort 挪进 shared/inbounds.ts，两个页面都要用它了。

web/views/DashboardPage.vue

@@ -9,7 +9,7 @@
  * 除了「检测公网 IP」，全部只读。
  */
 import { computed, onBeforeUnmount, onMounted, ref, watch } from 'vue'
-import { collectInbounds, inboundStatKey } from '@shared/inbounds.ts'
+import { collectInbounds, firstPort, inboundStatKey } from '@shared/inbounds.ts'
 import { flagEmoji, formatBytes, formatUptime } from '@shared/format.ts'
 import { ACTIVE_BYTES, ROUTE_WINDOW_MS, bucketRates, lastRate, windowBytes } from '@shared/telemetry.ts'
 import type { RouteSample } from '@shared/telemetry.ts'
@@ -29,7 +29,7 @@ import {
   totals,
   traffic,
 } from '../telemetry'
-import { firstPort, kernelPorts, modeLabel } from '../dashboard'
+import { kernelPorts, modeLabel } from '../dashboard'
 import { cssColor, themeTick } from '../theme'
 import EChart from '../components/EChart.vue'
 import ConfirmDialog from '../components/ConfirmDialog.vue'