initial commit on Federted servers

web/lib/reference-data.ts

@@ -0,0 +1,38 @@
+// Short-TTL cache with in-flight deduplication for the reference data the
+// bookmark detail sheet needs on every open (identity, kanban columns,
+// contacts, tags). Mutation sites call invalidateReference() so a just-created
+// tag/column/contact shows up immediately instead of after the TTL.
+
+export type ReferenceKind = 'me' | 'columns' | 'contacts' | 'tags'
+
+const PATHS: Record<ReferenceKind, string> = {
+  me: '/api/me',
+  columns: '/api/kanban/columns',
+  contacts: '/api/contacts',
+  tags: '/api/tags',
+}
+
+const TTL_MS = 30_000
+const cache = new Map<ReferenceKind, { at: number; promise: Promise<unknown> }>()
+
+export function invalidateReference(kind: ReferenceKind) {
+  cache.delete(kind)
+}
+
+// Resolves to null on any failure; failures are not kept cached.
+export function fetchReference<T = unknown>(kind: ReferenceKind): Promise<T | null> {
+  const hit = cache.get(kind)
+  if (hit && Date.now() - hit.at < TTL_MS) return hit.promise as Promise<T | null>
+  const promise = (async () => {
+    try {
+      const res = await fetch(PATHS[kind])
+      return res.ok ? ((await res.json()) as T) : null
+    } catch {
+      return null
+    }
+  })()
+  const entry = { at: Date.now(), promise }
+  cache.set(kind, entry)
+  void promise.then((v) => { if (v === null && cache.get(kind) === entry) cache.delete(kind) })
+  return promise
+}