fix: add root route so HF Space doesn't show 404

Polish repo for judges: move internal docs, clean winner refs, improve dashboard

[Push 3] Roopal: curriculum policy, verification spec, benchmark protocol, dashboard metrics, phase scoring

[Push 1] Roopal: enhance all docs with explicit winner-inspired patterns (KubeSRE, Bio, VRAM)

[Push 1] Roopal: scaffold docs, architecture, phase workflow

Add spec/contract files to main for Suyash: ARCHITECTURE, reward spec, scenarios, milestones, phase workflow