Coordinate AI retries and recover shared provider outages

Retry transient requests after one and three minutes and coordinate provider recovery across processes with bounded probe intervals. Preserve completed results when recovery bookkeeping fails, keep concurrent failure accounting accurate, and expose retry state in the UI.

web/src/common/components/AiAvailability/index.vue

@@ -0,0 +1,40 @@
+<script setup lang="ts">
+import type { ProviderAvailability } from "@@/apis/settings"
+import { listProviderAvailabilityApi } from "@@/apis/settings"
+import { useSessionScope } from "@@/composables/useSessionScope"
+
+const scope = useSessionScope()
+const states = ref<ProviderAvailability[]>([])
+const failed = ref(false)
+let timer: ReturnType<typeof setTimeout> | undefined
+let closed = false
+async function refresh() {
+  try {
+    const rows = await listProviderAvailabilityApi()
+    if (closed) return
+    scope.assertCurrent()
+    states.value = rows.filter(row => row.state !== "normal")
+    failed.value = false
+  } catch (error) {
+    if (!closed) {
+      failed.value = true
+      console.error(error)
+    }
+  } finally {
+    if (!closed) timer = setTimeout(refresh, 5000)
+  }
+}
+onMounted(refresh)
+onBeforeUnmount(() => {
+  closed = true
+  clearTimeout(timer)
+})
+</script>
+
+<template>
+  <el-alert v-if="failed" class="mb-3" type="warning" :closable="false" title="模型接入状态读取失败" />
+  <el-alert v-for="row in states" :key="row.provider_id" class="mb-3" type="warning" :closable="false">
+    {{ row.name }}：{{ row.state === 'probing' ? '正在单请求试探恢复' : '接入暂时不可用，等待恢复' }}。
+    下次尝试 {{ row.retry_at ? new Date(row.retry_at).toLocaleString() : '—' }}；等待期间保留任务。
+  </el-alert>
+</template>