Field editor: palette, select/move/resize/rotate, inspector, optimistic sync (#11) (#30)

Co-authored-by: Steve Dudenhoeffer <[email protected]>

web/src/components/ui/toast.tsx

@@ -0,0 +1,65 @@
+import { useEffect } from 'react'
+import { create } from 'zustand'
+import { cn } from '@/lib/cn'
+
+type ToastTone = 'info' | 'error'
+interface Toast {
+  id: number
+  message: string
+  tone: ToastTone
+}
+
+interface ToastState {
+  toasts: Toast[]
+  push: (message: string, tone?: ToastTone) => void
+  dismiss: (id: number) => void
+}
+
+let nextId = 1
+
+export const useToastStore = create<ToastState>((set) => ({
+  toasts: [],
+  push: (message, tone = 'info') => set((s) => ({ toasts: [...s.toasts, { id: nextId++, message, tone }] })),
+  dismiss: (id) => set((s) => ({ toasts: s.toasts.filter((t) => t.id !== id) })),
+}))
+
+/** Fire a toast from anywhere (including non-component code). */
+export const toast = {
+  info: (m: string) => useToastStore.getState().push(m, 'info'),
+  error: (m: string) => useToastStore.getState().push(m, 'error'),
+}
+
+// Param is `item`, not `toast`, so it doesn't shadow the module's `toast` export.
+function ToastItem({ item }: { item: Toast }) {
+  const dismiss = useToastStore((s) => s.dismiss)
+  useEffect(() => {
+    const t = setTimeout(() => dismiss(item.id), 4000)
+    return () => clearTimeout(t)
+  }, [item.id, dismiss])
+  return (
+    <div
+      role={item.tone === 'error' ? 'alert' : 'status'}
+      className={cn(
+        'pointer-events-auto rounded-md border px-3 py-2 text-sm shadow-md',
+        item.tone === 'error'
+          ? 'border-red-500/40 bg-red-500/10 text-red-700 dark:text-red-300'
+          : 'border-border bg-surface text-fg',
+      )}
+    >
+      {item.message}
+    </div>
+  )
+}
+
+/** Fixed stack of active toasts. Mount once near the app root. */
+export function Toaster() {
+  const toasts = useToastStore((s) => s.toasts)
+  if (toasts.length === 0) return null
+  return (
+    <div className="pointer-events-none fixed bottom-4 left-1/2 z-[60] flex -translate-x-1/2 flex-col items-center gap-2">
+      {toasts.map((t) => (
+        <ToastItem key={t.id} item={t} />
+      ))}
+    </div>
+  )
+}