Lobby: maps, map editor and tokens

DM map library (upload re-encoded with Pillow), map editor with prepared
enemies/NPCs, map on the lobby table with personal pan/zoom, draggable
tokens (players move their own, DM all), full/player view, live sync via
the WebSocket.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HJhXuLD2Z6hv3Wqeq9UL9K

DEPLOY.md

@@ -62,7 +62,7 @@ server {
     listen 80;
     server_name aw.yourdomain.tld;
 
-    client_max_body_size 1m;
+    client_max_body_size 13m;   # map uploads (the app itself limits them to 12 MB and keeps characters small)
 
     location / {
         proxy_pass http://127.0.0.1:8090;   # same as AW_PORT in .env
@@ -79,7 +79,7 @@ server {
 }
 ```
 
-Already running an older config? Add the last four lines inside `location /`, then `sudo nginx -t && sudo systemctl reload nginx`. Nothing else changes; the lobby still works without them, just with a few seconds of delay.
+Already running an older config? Add the last four lines inside `location /` and change `client_max_body_size` to `13m` (needed for map uploads, otherwise nginx answers 413), then `sudo nginx -t && sudo systemctl reload nginx`. Nothing else changes; the lobby still works without them, just with a few seconds of delay.
 
 ```bash
 sudo ln -s /etc/nginx/sites-available/aw /etc/nginx/sites-enabled/aw