v0.8.0: learned prices, estimates, runway, compare, export + docs site
New modes: prices (price table learned from your own billing ledger), estimate (cost a hypothetical workload at those prices, K/M/B suffixes), runway (burn-rate projections), compare (two accounts side by side), export (CSV/JSONL ledger for DuckDB). GitHub Pages docs site: https://logicinczo.github.io/zai-usage/ — 46 tests.