Add final submission demo and publish artifacts

fix: comparison tab (remove 4-bit quant, handle missing adapter, VRAM guard)

docs: finalize premium README with real training metrics and UI screenshots

feat(phase2-D2): Full 5-tab Observatory UI overhaul with Live Environment, Training Results, Research Story, API Explorer, System Health

Refactor ShiftLog-Gym for procedural multi-shift training

Refine Colab training stack (Unsloth+GRPO+W&B+HF publish)

Initial ShiftLog-Gym environment