Config-gated (open_publish): anyone publishes without the server key and
gets an owner token (128-bit, shown once, stored hashed) that manages only
that file. Per-address limits (X-Forwarded-For only from trusted_proxy,
bounded tables), global caps, idle expiry, reports, persisted blocks,
files list --sort, check, GET /healthz on the same listener, startup
warnings. The app asks the server first, publishes without a key when it
is open, shows the owner token once, the host/terms line, the expiry date
and a report button; collab.serverInfo, collab.manageFile, collab.report
and pref.publishServer for MCP/CLI. Protocol additions stay within
version 2, gated like signals.