PWA for iPhone and iPad: PNG icons, splash screens, manifest; stay signed in for 180 days

- iOS ignores SVG touch icons: add 120/152/167/180 apple-touch-icons, 192/512 and maskable manifest icons,
  and 25 splash screens (every iPhone size, iPad portrait+landscape incl. 12.9")
- Icons and splash screens are public so iOS can fetch them without a session
- Manifest: id, scope, categories, shortcuts; iOS standalone polish (no callout, no overscroll)
- Sessions last SESSION_DAYS (default 180) and renew daily while in use
- tools/make-icons.py regenerates the artwork

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docker-compose.yml

@@ -20,6 +20,7 @@ services:
       ONLYOFFICE_JWT_SECRET: ${ONLYOFFICE_JWT_SECRET:-}    # same value as the OnlyOffice server's JWT secret
       PUBLIC_URL: ${PUBLIC_URL:-}                           # e.g. https://hub.necloud.us (OnlyOffice posts saved edits here)
       HUB_SETUP_CODE: ${HUB_SETUP_CODE:-}                   # first passkey; if empty, a code is printed in the log
+      SESSION_DAYS: ${SESSION_DAYS:-180}                     # how long you stay signed in when idle; using the app renews it
       COOKIE_SECRET: ${COOKIE_SECRET:-}                     # optional; auto-generated and kept in /data if empty
     volumes:
       - hub-data:/data   # passkeys, calendar links and the session secret live here