Graywolf RXT test build 416ee322

Adds APRS reception and transmission through an existing AGW Packet Engine server, with radio-port selection and automatic reconnection.

Install and restart Graywolf, then reload its web page. On the KISS page, add a TCP Client and select AGWPE (APRS client). Enter the server address, TCP port (normally 8000) and AGWPE radio port (1-16). Use 127.0.0.1 when both applications run on the same computer.

Enable the TCP/IP application interface in AGWPE and permit the Graywolf computer. Assign a Graywolf APRS channel with external TNC backing, without an audio input device. Enable interface transmission when needed. Use one interface/channel per remote radio port. Existing KISS settings are preserved.

Tests: Go tests, binary protocol fixtures, reconnect race tests, 585 Web tests, browser configuration tests and the Web build pass. DEV still needs to validate with real AGWPE and radio hardware.

Limits: APRS UI frames only. No AGWPE-managed connected packet sessions or AGWPE username/password login. Do not connect to Graywolf's own AGW server.

Documentation: https://github.com/moricef/graywolf/blob/rxt-416ee322/docs/handbook/agwpe.html#client

Base version: 0.14.14
Commit: 416ee32