Initial commit: TaskPool React panel

- React frontend with route-level code splitting
- Backend rebranded from Baihu to TaskPool
- DB brand migration script and local compatibility

web/src/lib/toast.ts

@@ -0,0 +1,51 @@
+export type ToastType = 'success' | 'error' | 'info' | 'warning'
+
+export interface ToastItem {
+  id: number
+  type: ToastType
+  message: string
+  duration: number
+}
+
+type Listener = (items: ToastItem[]) => void
+
+let seq = 1
+let items: ToastItem[] = []
+const listeners = new Set<Listener>()
+
+function emit() {
+  listeners.forEach((fn) => fn([...items]))
+}
+
+function push(type: ToastType, message: string, duration = 3000) {
+  const id = seq++
+  const item: ToastItem = { id, type, message, duration }
+  items = [...items, item]
+  emit()
+  if (duration > 0) {
+    window.setTimeout(() => {
+      dismiss(id)
+    }, duration)
+  }
+  return id
+}
+
+export function dismiss(id: number) {
+  items = items.filter((t) => t.id !== id)
+  emit()
+}
+
+export function subscribeToast(listener: Listener) {
+  listeners.add(listener)
+  listener([...items])
+  return () => {
+    listeners.delete(listener)
+  }
+}
+
+export const toast = {
+  success: (message: string, duration?: number) => push('success', message, duration),
+  error: (message: string, duration?: number) => push('error', message, duration ?? 4000),
+  info: (message: string, duration?: number) => push('info', message, duration),
+  warning: (message: string, duration?: number) => push('warning', message, duration),
+}