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/lock.post.ts

@@ -1,4 +1,5 @@
-export default defineEventHandler((event) => {
-  clearLibraryUnlock(event)
+export default defineEventHandler(async (event) => {
+  const body = await readBody<{ folderId?: string }>(event).catch(() => ({} as { folderId?: string }))
+  clearFolderUnlock(event, body?.folderId)
   return publicLibrary(event)
 })