feat(monitor): 30-day raw retention + timeline 4-tier style + CC template seed + JSON format button

- History retention 1d → 30d（60s × 30d ≈ 43200 行/model，PG 无压力）；
  ComputeAvailability* 不再 UNION rollup 表，直接扫 histories 精度更高。
- Timeline bar 四级高度+颜色双重编码：operational 高+绿 / degraded 中+黄 /
  failed+error 短+红 / 未测试 很短+灰。
- migration 113 seed「Claude Code 伪装」模板（ON CONFLICT DO NOTHING）。
  user_id 用 legacy 格式（user_<64hex>_account_<uuid>_session_<uuid>），
  避免新版 JSON 字符串内嵌 JSON 在编辑器里一长串 \" 难读。
- MonitorAdvancedRequestConfig 加「格式化」按钮 + white-space:pre
  让 body textarea 对长字符串不压扁。

frontend/src/components/admin/monitor/MonitorAdvancedRequestConfig.vue

@@ -38,12 +38,24 @@
 
     <!-- Body JSON (仅当 mode != off) -->
     <div v-if="bodyOverrideMode !== 'off'">
-      <label class="input-label">{{ t('admin.channelMonitor.advanced.bodyJson') }}</label>
+      <div class="mb-1 flex items-center justify-between">
+        <label class="input-label !mb-0">{{ t('admin.channelMonitor.advanced.bodyJson') }}</label>
+        <button
+          type="button"
+          class="text-xs text-primary-600 hover:underline disabled:cursor-not-allowed disabled:text-gray-400 disabled:no-underline dark:text-primary-400"
+          :disabled="!bodyText.trim()"
+          @click="formatBody"
+        >
+          {{ t('admin.channelMonitor.advanced.bodyJsonFormat') }}
+        </button>
+      </div>
       <textarea
         v-model="bodyText"
-        rows="8"
+        rows="10"
         :placeholder="bodyPlaceholder"
         class="input font-mono text-xs"
+        style="white-space: pre; overflow-wrap: normal; overflow-x: auto;"
+        spellcheck="false"
         @blur="commitBody"
       />
       <p v-if="bodyError" class="mt-1 text-xs text-red-500">{{ bodyError }}</p>
@@ -158,6 +170,25 @@ function commitBody() {
   }
 }
 
+function formatBody() {
+  const trimmed = bodyText.value.trim()
+  if (trimmed === '') return
+  try {
+    const parsed = JSON.parse(trimmed)
+    bodyText.value = JSON.stringify(parsed, null, 2)
+    bodyError.value = ''
+    // 同步把校验过的对象提交，避免格式化后焦点未移走时父组件读到旧值
+    if (parsed && typeof parsed === 'object' && !Array.isArray(parsed)) {
+      emit('update:bodyOverride', parsed as Record<string, unknown>)
+    }
+  } catch (e) {
+    bodyError.value =
+      t('admin.channelMonitor.advanced.bodyJsonError') +
+      ': ' +
+      (e instanceof Error ? e.message : String(e))
+  }
+}
+
 function serializeBody(body: Record<string, unknown> | null): string {
   if (!body || Object.keys(body).length === 0) return ''
   return JSON.stringify(body, null, 2)

frontend/src/components/user/monitor/MonitorTimeline.vue

@@ -59,19 +59,21 @@ interface Bar {
   title: string
 }
 
+// 4 级高度 + 颜色双重编码：高=好+绿，短=坏+红，灰=未测试。
+// 长绿(正常) > 中黄(降级) > 短红(失败/系统错误) > 很短灰(未测试)。
 const STATUS_HEIGHT: Record<string, number> = {
   operational: 100,
-  degraded: 70,
-  failed: 55,
+  degraded: 65,
+  failed: 35,
   error: 35,
-  empty: 20,
+  empty: 15,
 }
 
 const STATUS_COLOR: Record<string, string> = {
   operational: 'bg-emerald-500',
   degraded: 'bg-amber-500',
   failed: 'bg-red-500',
-  error: 'bg-gray-400 dark:bg-dark-500',
+  error: 'bg-red-500',
   empty: 'bg-gray-300 dark:bg-dark-600',
 }