Adds a floating LoRA adapter status panel to the Nexus scene. The panel
shows which fine-tuning adapters are active, their base model, and
strength percentage via a bar indicator. Data is loaded from
lora-status.json (with fallback stub), refreshed every 60 s.
Fixes#277
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>