feat: add deepseek-harness workbench plugin and console diagnosis API

- console: GET /api/workflows/{id}, /runs/{run_id}, /runs/{run_id}/diagnosis
  (journal trace + sanitized bounded log tails, workflow/run pairing enforced)
- workbench/: dsh 宿主插件（7 个工作流工具、中文系统提示词、失败监控器、
  本机回环桥接服务）+ 侧边栏面板客户端包（sidebar.footer.action 与
  shell.overlay 追加插槽）+ 降级独立面板 + 一键启动脚本
- adapters/browser: 收敛 looks_like_login_url 到共享层，修复
  jd_main_image_collector 对 gyxx_flow.accounts 的越层导入
- tests: 新端点覆盖；replay_policy 断言对齐已迁移的 catalog（repeatable）

workbench/plugin/client/src/Toasts.jsx

@@ -0,0 +1,74 @@
+/** 失败告警浮层：轮询桥接告警，新失败弹出 toast，可一键发起诊断会话。 */
+
+import { useEffect } from 'react'
+import { useSyncExternalStore } from 'react'
+import { getState, subscribe, update, dismissToast, pushToast } from './store.js'
+import { api } from './api.js'
+
+function useWorkbench() {
+  return useSyncExternalStore(subscribe, getState)
+}
+
+export function Toasts() {
+  const s = useWorkbench()
+
+  useEffect(() => {
+    let stopped = false
+    let timer = null
+    const poll = async () => {
+      try {
+        const payload = await api.alerts()
+        const fresh = (payload.alerts ?? []).filter(
+          (alert) => !alert.seen && !getState().seenAlertIds[alert.id],
+        )
+        if (fresh.length) {
+          const seen = { ...getState().seenAlertIds }
+          for (const alert of fresh) {
+            seen[alert.id] = true
+            pushToast({ kind: 'failed', text: `工作流「${alert.name}」运行失败`, alert })
+          }
+          update({ seenAlertIds: seen })
+        }
+      } catch {
+        // 桥接离线时静默
+      }
+      if (!stopped) timer = setTimeout(poll, 30_000)
+    }
+    timer = setTimeout(poll, 8_000)
+    return () => {
+      stopped = true
+      if (timer) clearTimeout(timer)
+    }
+  }, [])
+
+  if (!s.toasts.length) return null
+  return (
+    <div className="gyxxwb-toasts">
+      {s.toasts.map((toast) => (
+        <div key={toast.id} className={`gyxxwb-toast gyxxwb-toast-${toast.kind}`}>
+          <span className="gyxxwb-toast-text">{toast.text}</span>
+          {toast.alert && (
+            <button
+              type="button"
+              onClick={async () => {
+                try {
+                  await api.ask({ workflow_id: toast.alert.workflow_id, action: 'diagnose' })
+                  await api.markAlertSeen(toast.alert.id).catch(() => {})
+                  pushToast({ kind: 'ok', text: '已创建诊断会话，请在左侧会话列表查看' })
+                } catch (error) {
+                  pushToast({ kind: 'error', text: `创建会话失败：${error.message}` })
+                }
+                dismissToast(toast.id)
+              }}
+            >
+              立即诊断
+            </button>
+          )}
+          <button type="button" title="关闭" onClick={() => dismissToast(toast.id)}>
+            ✕
+          </button>
+        </div>
+      ))}
+    </div>
+  )
+}