v0.50.3 in beta fix and stability

Some stability and fixes ; also giving capability to upload the .yaml file in a .zip format. Should make it easier than having to scp to the controller.

Let me know feedback.

## 0.50.3

- Restructure POLYGLOT_CONFIG for devfile-first setup with upload and SSH paths
- Add starter data/mqtt-devices.yaml template
- Trim README to capability and installation overview only

## 0.50.2
- Extract device discovery and topic registration into discovery module
- Unwrap Tasmota StatusSNS payloads once in Controller before routing to nodes
- Skip duplicate status topic registration on re-discovery
- Remove dead pass stubs from node modules
- Fix disconnect handler exception path

## 0.50.1
- Fix startup handler gate when CUSTOMPARAMS arrives last
- Fix poll heartbeat guard to respect controller ready state
- Accept documented devlist JSON arrays alongside legacy dict upserts
- Merge devfile and devlist configuration as documented
- Resubscribe MQTT topics after DISCOVER when already connected
- Add MQTT connect timeout instead of infinite wait
- Fix sensor message routing to use two-argument updateInfo
- Refactor config loading, device registry, and MQTT bridge modules
- Add MQTasmotaSensor base class for shared Tasmota sensor behavior
- Unsubscribe MQTT topics when nodes are removed
- Add legacy config regression test suite