archivist 0.4.0

• For agents: an MCP server at /mcp (Streamable HTTP, stateless, the same token) with nine
  tools: search the library, list and open works, look at a page or a frame (scaled down for a
  model), read and save progress, follow events, list profiles. /api/v1/search, an OpenAPI 3.1
  document at /api/v1/openapi.json, and /llms.txt.
• Safe to publish behind a reverse proxy: a request with forwarding headers is never trusted
  (and its client address is read only from ARCHIVIST_PROXIES, loopback by default), browser sessions
  replace the token in the cookie (revocable from Perfiles), wrong tokens are logged with the
  real address and limited to 10 per 15 minutes, hardening headers and HSTS, DNS rebinding
  closed, and video stays home unless ARCHIVIST_PROXIED_VIDEO=on.
• A new look: Fraunces and Inter (bundled, no font CDN), a "continue" hero with the cover's
  colors, glass header, covers with type badges and progress, volumes and episodes as cards
  with their own thumbnails, seasons as tabs, skeletons while loading, colored profiles.
• Smaller images for grids: ?w= on covers, pages and frames (cached), and ?at= for a frame
  at a share of the running time.
• Fix: two requests for the same frame at once could fail.
• Upgrading: browsers log in once more (the old token cookie is no longer read).