Improved chat history (pagination) and added API status indicators.

Introduces background requests and notifications support.

Minor improvements to indicate current connectivity state and connected server.

A new dedicate web variant (PWA) for the Rhea Generative Client is now available at: https://rhea.oddineers.co.uk. It features the majority of the functionality found in the Chrome Extension and several enhancements. The PWA variant offers an alternative method to utilise the Rhea Client and where supported provides installation method for devices (and browsers) with PWA…