fix: adjust exact_match threshold to 0.95 to work with clamped breakdown values

fix: widen reward clamp from (0.001,0.999) to (0.01,0.99) — evaluator rounds values

Fix: clamp rewards to (0.001, 0.999) — evaluator requires strictly (0, 1)

Restructure to match official OpenEnv reference environments

Add expert tasks, blind mode, step cost/bonus, improved prompting

Add /metadata and /mcp endpoints for openenv runtime validation

Add root endpoint to fix 404 on HF Space homepage

feat: OpenEnv SQL Query Environment