init: arcadia-admin — admin webapp for arcadia-core, cloned from vibespace

Initial commit. Spun up via the docs/STARTER.md recipe: cp from vibespace,
reset git, rename package, set brand to "Arcadia Admin" with Shield icon
in app/lib/identity.ts.

Inherits the full Crema sibling-lib wiring including @crema/arcadia-client
(typed HTTP + Phoenix Channels realtime against arcadia-core) and
@crema/arcadia-auth-ui (login/signup/password-reset/2FA forms). The /login
route already renders <LoginForm>; <ArcadiaProvider> in app/root.tsx reads
VITE_ARCADIA_URL (default localhost:4000) and VITE_ARCADIA_TENANT (default
"default").

CLAUDE.md and README rewritten to frame this as the admin app for
arcadia-core. docs/STARTER.md removed — arcadia-admin is a leaf consumer,
not a downstream starter.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/lib/notifications.ts

@@ -0,0 +1,155 @@
+// Notifications — small reactive store for in-app toasts/inbox items.
+// Pair with @crema/notification-ui's <ToastProvider /> for transient toasts;
+// this store is for the appbar bell's persistent inbox.
+
+import { useEffect, useSyncExternalStore } from "react"
+
+export type NotificationKind = "info" | "success" | "warning" | "error"
+
+export type AppNotification = {
+  id: string
+  kind: NotificationKind
+  title: string
+  body?: string
+  // Optional href to open when the row is clicked.
+  href?: string
+  createdAt: number
+  readAt?: number
+}
+
+const STORAGE_KEY = "crema.notifications"
+const CHANGE_EVENT = "crema:notifications-change"
+const MAX_ITEMS = 200
+
+function newId(): string {
+  return `n-${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 6)}`
+}
+
+function readFromStorage(): AppNotification[] {
+  if (typeof window === "undefined") return []
+  try {
+    const raw = localStorage.getItem(STORAGE_KEY)
+    if (!raw) return []
+    const parsed = JSON.parse(raw)
+    if (!Array.isArray(parsed)) return []
+    return parsed.filter(
+      (n): n is AppNotification =>
+        n &&
+        typeof n.id === "string" &&
+        typeof n.title === "string" &&
+        typeof n.createdAt === "number" &&
+        ["info", "success", "warning", "error"].includes(n.kind),
+    )
+  } catch {
+    return []
+  }
+}
+
+function writeToStorage(items: AppNotification[]) {
+  if (typeof window === "undefined") return
+  const trimmed = items.slice(0, MAX_ITEMS)
+  try {
+    localStorage.setItem(STORAGE_KEY, JSON.stringify(trimmed))
+    window.dispatchEvent(new CustomEvent(CHANGE_EVENT))
+  } catch {
+    /* quota — drop silently */
+  }
+}
+
+export function loadNotifications(): AppNotification[] {
+  return readFromStorage()
+}
+
+export function addNotification(
+  n: Omit<AppNotification, "id" | "createdAt">,
+): AppNotification {
+  const next: AppNotification = {
+    ...n,
+    id: newId(),
+    createdAt: Date.now(),
+  }
+  writeToStorage([next, ...readFromStorage()])
+  return next
+}
+
+export function markRead(id: string) {
+  const items = readFromStorage().map((n) =>
+    n.id === id ? { ...n, readAt: Date.now() } : n,
+  )
+  writeToStorage(items)
+}
+
+export function markAllRead() {
+  const now = Date.now()
+  const items = readFromStorage().map((n) =>
+    n.readAt ? n : { ...n, readAt: now },
+  )
+  writeToStorage(items)
+}
+
+export function dismiss(id: string) {
+  writeToStorage(readFromStorage().filter((n) => n.id !== id))
+}
+
+export function dismissAll() {
+  writeToStorage([])
+}
+
+let cached: AppNotification[] | null = null
+
+function subscribe(cb: () => void): () => void {
+  const onChange = () => {
+    cached = null
+    cb()
+  }
+  window.addEventListener(CHANGE_EVENT, onChange)
+  window.addEventListener("storage", (e) => {
+    if (e.key === STORAGE_KEY) onChange()
+  })
+  return () => window.removeEventListener(CHANGE_EVENT, onChange)
+}
+function getSnapshot(): AppNotification[] {
+  if (!cached) cached = readFromStorage()
+  return cached
+}
+function getServerSnapshot(): AppNotification[] {
+  return []
+}
+
+export function useNotifications(): AppNotification[] {
+  const value = useSyncExternalStore(subscribe, getSnapshot, getServerSnapshot)
+  useEffect(() => {
+    cached = null
+  }, [])
+  return value
+}
+
+export function unreadCount(items: AppNotification[]): number {
+  return items.filter((n) => !n.readAt).length
+}
+
+/** Seed a few demo notifications on first load so the bell isn't empty. */
+export function seedIfEmpty() {
+  if (typeof window === "undefined") return
+  if (localStorage.getItem(STORAGE_KEY)) return
+  const now = Date.now()
+  const seed: AppNotification[] = [
+    {
+      id: newId(),
+      kind: "info",
+      title: "Welcome",
+      body: "Tag elements with data-action and the assistant can drive them.",
+      href: "/assistant",
+      createdAt: now - 60_000,
+    },
+    {
+      id: newId(),
+      kind: "success",
+      title: "Profile saved",
+      body: "Your display name and avatar are live across the app.",
+      href: "/profile",
+      createdAt: now - 5 * 60_000,
+    },
+  ]
+  writeToStorage(seed)
+}