v0.50.11 in production: fixes and making common

Fixed where there is a delay at normal startup for the waiting on user connection message to clear. As well have fixed the upload to the data folder for your devfile. This and other communications and moving to the modern UD standards on things. Tests out on my system, give it a try:

## 0.50.11

- Fix config overwrite on update: stop re-injecting example devlist/devfile and MQTT defaults on every parameter load; clear customParams in server.json so plugin updates do not reset saved Polyglot configuration

- Clear waiting notice when discovery or MQTT connection fails

## 0.50.10

- Fix stop() crash on early shutdown: remove legacy mqttc teardown path that raised AttributeError when discovery failed before the MQTT bridge was created (common during eisy-ui config)

## 0.50.9

- Clear MQTT waiting notice promptly after broker connects: drain Paho callbacks at startup and at DISCOVER so "Waiting on user MQTT connection" does not linger for a full poll cycle when the broker is already up

- Fix devfile path resolution: bare filename (e.g. virtualconfig.yaml) resolves to data/<name>; empty devfile no longer silently loads mqtt-devices.yaml — use an explicit devfile or devlist

- Fix startup log (was incorrectly labeled "Virtual Devices")

- PG3 store manifest server.json) with executable udi-mqtt-pg3x.py — use Update from the store

- Rename entry script from mqtt-poly.py to udi-mqtt-pg3x.py

- Standard bootstrap (error handling; version in VERSION / profile/version.txt / server.json)

- Developer toolchain: uv, pytest profile sync test, Makefile, CONTRIBUTING (runtime install unchanged: install.sh + requirements.txt)

Edited 40 minutes ago40 min by sjenkins