feat(admin): file manager — search, type tabs (image/video/AE), library picker

- FileManager: type tabs (همه/تصاویر/ویدیوها/صدا/پروژه‌های AE و سایر) + name
  search (uses file_type + search params the file svc already supports; type
  values capitalized to match the enum), video thumbnails via <video>, AE/zip
  shown under "AE و سایر"; delete + copy-URL retained
- FilePicker: reusable modal to re-choose an existing file from the library
  (search + filter + click to pick)
- FileUploadField: new "از کتابخانه" button on every upload field → pick from
  library instead of re-uploading; picker auto-filters by the field's accept
- shared src/lib/admin-files.ts helpers (fileUrl/isImage/isVideo/fetchFiles)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/lib/admin-files.ts

@@ -0,0 +1,58 @@
+import { MINIO_PUBLIC_URL } from "@/lib/files";
+
+export interface FileItem {
+  id: string;
+  name: string;
+  mime_type?: string;
+  file_type?: string; // Image | Video | Audio | Voiceover | Document | Other
+  size_bytes?: number;
+  minio_bucket?: string;
+  minio_key?: string;
+  cdn_url?: string | null;
+  file_address?: string | null;
+  thumbnail_url?: string | null;
+  created_at?: string;
+}
+
+/** Type filter tabs — values are the exact (capitalized) FileKind enum the API expects. */
+export const FILE_TYPE_TABS: { v: string; l: string }[] = [
+  { v: "", l: "همه" },
+  { v: "Image", l: "تصاویر" },
+  { v: "Video", l: "ویدیوها" },
+  { v: "Audio", l: "صدا" },
+  { v: "Other", l: "پروژه‌های AE و سایر" },
+];
+
+export function fileUrl(f: FileItem): string | null {
+  if (f.cdn_url) return f.cdn_url;
+  if (f.file_address) return f.file_address;
+  if (f.minio_key) return `${MINIO_PUBLIC_URL}/${f.minio_bucket ?? "user-uploads"}/${f.minio_key}`;
+  return null;
+}
+
+export function isImage(f: FileItem): boolean {
+  return f.file_type === "Image" || (f.mime_type ?? "").startsWith("image/") || /\.(png|jpe?g|gif|webp|svg|avif)$/i.test(f.name);
+}
+export function isVideo(f: FileItem): boolean {
+  return f.file_type === "Video" || (f.mime_type ?? "").startsWith("video/") || /\.(mp4|webm|mov|m4v|mkv)$/i.test(f.name);
+}
+export function isAep(f: FileItem): boolean {
+  return /\.(aep|aepx|zip)$/i.test(f.name);
+}
+
+export function humanSize(n?: number): string {
+  if (!n) return "—";
+  const u = ["B", "KB", "MB", "GB"];
+  let i = 0, v = n;
+  while (v >= 1024 && i < u.length - 1) { v /= 1024; i++; }
+  return `${v.toFixed(v < 10 && i > 0 ? 1 : 0)} ${u[i]}`;
+}
+
+/** Fetch files from the admin gateway with optional search + type filter. */
+export async function fetchFiles(search: string, fileType: string, page = 1, pageSize = 60): Promise<FileItem[]> {
+  const qs = new URLSearchParams({ page: String(page), pageSize: String(pageSize), page_size: String(pageSize) });
+  if (search) qs.set("search", search);
+  if (fileType) qs.set("file_type", fileType);
+  const r = await fetch(`/api/admin/resource/files?${qs.toString()}`, { cache: "no-store" }).then((x) => x.json()).catch(() => null);
+  return r?.items ?? r?.data ?? (Array.isArray(r) ? r : []);
+}