v0.2.1 — Correct turn usage across native counter sources

Fixes turn usage showing “Unobserved” when native request totals and legacy token-count events have different historical baselines. Reports now keep the two sources separate and prefer the selected turn's validated native counter, keeping its Task and turn totals together.

True same-source resets, invalid records, source changes, and bounded-tail turn-counter decreases remain unavailable. Preview and original Stop files remain immutable; completion checks still stop at the selected turn boundary.

Validation: 182 tests, Ruff, repository/docs/manifest checks, and sensitive-data scan passed locally. An isolated installation exercised real packaged hooks: preview 600 → Stop 800 → completed turn 1,000, excluding the next turn and preserving original receipts. Read-only native inspection also confirmed the reported source mismatch and recovered the affected turn's explicit native count; private data is not published.

After updating, review the changed hooks in Codex CLI /hooks and start a new Task. Existing Tasks can retain a pinned older runtime, and old inline cards do not refresh.