Three places claimed there was no PTT line, and one of them named the wrong pin
(GPIOC rather than PB10). All now say the same thing: PTT works, but not through
the key table, because the firmware reads its own pin instead of scanning it as a
matrix key.
Documents the transmit bar's two gates -- FUNCTION_TRANSMIT and gSetting_mic_bar,
the latter already on because blank flash reads 0xFF -- and why the release path
gets more attention than the press: a stuck PTT leaves every later test running
against a transmitting radio.
Also records the '.key' vs '.key[data-key]' trap for whoever adds the next
non-key button.
Rejects unknown names in the server rather than letting them reach QMP as an
error. A test parses keypad_key_names out of qemu/py32f071.c and fails if the
lists drift, so adding a key to the model cannot silently leave the web UI
behind.
PTT is deliberately absent: the model wires it separately on GPIOC, so the press
property rejects the name.
mckero