VibeServer 3.1.18 — multi-radio compatibility, admin takeover, and the landing that overruled you

VibeServer for macOS 3.1.18 — the same build the Pi runs, from the same source tree.

The whole release is about multi-radio compatibility: making a front door with several
receivers behind it behave the same way for every client — the browser, the iPhone app and the
watch — and it took most of a day of chasing symptoms that turned out to be the same few faults
wearing different clothes.

Admin and takeover

• Admin is exclusive, and the newest login wins. Leave a session open on the Mac, and you can
  take it back from your phone. The displaced client is demoted, not disconnected, and is now
  told — a control that silently stops working reads as a broken server.
• Holding the password is no longer the same as asking to interrupt. A client replays its
  stored credential on every automatic reconnect, so returning from the background used to throw
  the current listener off; with two of your own clients open they took the radio off each other
  indefinitely. Intent now travels with the credential and is one-shot.
• The take-over box on the IN USE page works on a multi-radio server. It proved the password to
  the front door, which owns no radio, so the receiver refused a credential it had never issued.
• Wrong passwords now say so instead of silently returning you to the same page.

Tuning

• The landing frequency no longer overrules a listener who has already tuned. Reconnect with a
  station remembered and you land on it, not on the receiver's default.
• An admin taking a receiver back keeps their own frequency.
• A lone listener on a receiver with no locked window can tune outside the captured band again —
  the radio moves with them.

Decoders and display

• BIG on a text decoder now means TALLER, not wider. RTTY lines are short, so a wider box was
  just more black; the previous fix raised a maximum, which permits growth and causes none.
• AF ticks, IF NARROW and CEQ colours now render in the app as they always did in the browser.

Under the hood

• Per-listener noise reduction, IMS, CEQ and noise blanking.
• The adaptive IF shadow filter was being rebuilt fifteen times a second and had therefore never
  once engaged since it shipped. It does now.
• A deadlock, an aborting close() that discarded every "here's why" message, and a connection log
  that recorded visits with no address — all fixed.

Requires macOS 14 or later. Notarised and stapled; it opens without a Gatekeeper warning.