Enrich per-event RST/VCC labels (ATR STARTS / power-up) + decode server-side

- decode_line_event adds human label: RST de-asserted->ATR STARTS,
  VCC applied->VCC ON (power-up); keep canonical event string
- Enable rst/vcc in DB decode dispatch so PWA receives decoded
  (fixes bare RESET/VCC fallback and a latent showDetail crash)
- PWA line_event_label/showDetail render decoded.label
- Bump 1.22.1, SW cache v32->v33; +1 test

simtrace2_pysniff/__init__.py

@@ -6,7 +6,7 @@ from .gsmtap import GsmtapSender, GsmtapReceiver
 from .pcap import PcapWriter
 from .dump import FileDumper, format_message
 
-__version__ = '1.22.0'
+__version__ = '1.22.1'
 __all__ = [
     'SniffSession',
     'DeviceDisconnected',