fix: use absolute path for allowed_paths

fix: allow assets path in Gradio launch and restore absolute model path

fix: pin gradio==5.50.0 + restore theme/css in Blocks + type=messages Chatbot

fix: migrate theme/css to launch() for Gradio 6 compatibility

fix: move theme/css to gr.Blocks() constructor + add Chatbot type='messages'

feat: BioOps Twin v1.0 — Enterprise-Grade Digital Twin for Lab Centrifuge Calibration