v0.2.0

v0.2.0 — billing correctness and production hardening.

• DeepSeek policies carry validity windows; unaudited/retired intervals fail closed
• canonical live/replay attribution and messageId-idempotent aggregation
• native-currency money semantics (costUsd + costNative/nativeCurrency)
• append-only JSONL ledger with corruption recovery and health reporting
• today-spend official-only with Asia/Shanghai accounting timezone and caching
• POST-only side-effecting refresh routes
• CI: tests, generated-file drift check, pack check