WA Archiver v1.8.0

Added

• Encrypted backups — optional passphrase on JSON backups. Downloads are
  sealed with AES-GCM-256 (PBKDF2-SHA256, 310k iterations, random salt+IV)
  entirely in the browser via WebCrypto; the passphrase never leaves the
  device. Restoring an encrypted file asks for the passphrase and rejects
  wrong ones without touching the database.
• Smart collections — three auto-computed, read-only chat folders:
  🖼️ Media (chats with media), ⏱️ Active this week, 📊 Biggest (top 5 by
  volume). No setup; they update live with the chat list.
• Per-chat themes — pick any of the 17 themes for a single chat from the
  Customize (wallpaper) popover. While that chat is open the whole look
  recolors; switching away snaps back to the app theme. Reset any time.

Changed

• mediaCount now counts every media-typed message, even when the file
  wasn't included in the export ("not in export" tiles) — the Media smart
  collection and chat badges reflect what the chat actually contains.
• Chat tools → "Media gallery" opens the global Media Hub (shared albums +
  date-range filter) pre-filtered to the current chat.

Fixed

• /api/media-index skipped media-typed messages without a stored file, so
  demo/synthetic media never appeared in the global Media Hub.