Add per-user library settings, folder passwords, and a still picker.

Settings manages folders, thumbnail defaults, and passwords for the signed-in account, and choosing an image now browses saved stills instead of only the desktop file dialog.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/api/library/folders.post.ts

@@ -1,6 +1,6 @@
 export default defineEventHandler(async (event) => {
-  assertLibraryAccess(event)
+  const { owner } = assertLibraryOwner(event)
   const body = await readBody<{ name?: string }>(event)
-  const folder = await createFolder(String(body?.name || ''))
-  return folder
+  const folder = await createFolder(owner, String(body?.name || ''))
+  return publicFolder(event, folder)
 })