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/library.ts

@@ -0,0 +1,125 @@
+// Library — saved artifacts. Today: conversation snapshots.
+// Tomorrow: snippets, prompts, generated documents.
+
+import { useEffect, useSyncExternalStore } from "react"
+
+export type LibraryItem = {
+  id: string
+  kind: "conversation" | "snippet"
+  title: string
+  // Free-form body. For "conversation": markdown transcript. For "snippet": text.
+  content: string
+  tags: string[]
+  // Optional metadata.
+  agentName?: string
+  agentRole?: string
+  threadId?: string
+  messageCount?: number
+  createdAt: number
+}
+
+const STORAGE_KEY = "crema.library"
+const CHANGE_EVENT = "crema:library-change"
+const MAX_BYTES = 1_500_000
+
+export function newLibraryId(): string {
+  return `lib-${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 6)}`
+}
+
+function isLibraryItem(v: unknown): v is LibraryItem {
+  if (!v || typeof v !== "object") return false
+  const x = v as LibraryItem
+  return (
+    typeof x.id === "string" &&
+    (x.kind === "conversation" || x.kind === "snippet") &&
+    typeof x.title === "string" &&
+    typeof x.content === "string" &&
+    Array.isArray(x.tags) &&
+    typeof x.createdAt === "number"
+  )
+}
+
+function readFromStorage(): LibraryItem[] {
+  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(isLibraryItem)
+  } catch {
+    return []
+  }
+}
+
+function writeToStorage(items: LibraryItem[]) {
+  if (typeof window === "undefined") return
+  let trimmed = items
+  let serialized = JSON.stringify(trimmed)
+  while (serialized.length > MAX_BYTES && trimmed.length > 1) {
+    trimmed = trimmed.slice(0, -1)
+    serialized = JSON.stringify(trimmed)
+  }
+  try {
+    localStorage.setItem(STORAGE_KEY, serialized)
+    window.dispatchEvent(new CustomEvent(CHANGE_EVENT))
+  } catch {
+    /* quota — bail */
+  }
+}
+
+export function loadLibrary(): LibraryItem[] {
+  return readFromStorage()
+}
+
+export function addLibraryItem(item: Omit<LibraryItem, "id" | "createdAt">): LibraryItem {
+  const next: LibraryItem = {
+    ...item,
+    id: newLibraryId(),
+    createdAt: Date.now(),
+  }
+  const items = readFromStorage()
+  writeToStorage([next, ...items])
+  return next
+}
+
+export function deleteLibraryItem(id: string) {
+  const items = readFromStorage().filter((x) => x.id !== id)
+  writeToStorage(items)
+}
+
+export function updateLibraryItem(id: string, patch: Partial<LibraryItem>) {
+  const items = readFromStorage().map((x) =>
+    x.id === id ? { ...x, ...patch } : x,
+  )
+  writeToStorage(items)
+}
+
+let cached: LibraryItem[] | 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(): LibraryItem[] {
+  if (!cached) cached = readFromStorage()
+  return cached
+}
+function getServerSnapshot(): LibraryItem[] {
+  return []
+}
+
+export function useLibrary(): LibraryItem[] {
+  const value = useSyncExternalStore(subscribe, getSnapshot, getServerSnapshot)
+  useEffect(() => {
+    cached = null
+  }, [])
+  return value
+}