Context Mode Files

FinOps accuracy and context-savings reporting

Follow-up to v1.0.167's per-turn cost capture. This release corrects how savings and cost are measured and reported.

Fixes

• Context-savings bar accuracy. ctx stats previously rendered "With context-mode: 1 B / 100% kept out" on tool-heavy sessions. The "With context-mode" figure now reflects the real bytes the model paid to access kept-out content (ctx_search + ctx_fetch_and_index returns), not sandbox compute output, so the kept-out ratio is honest.
• With/without ratio for the platform. The plugin now forwards bytes_retrieved (the retrieval access cost) alongside bytes_avoided, so org-level reporting can derive the full kept-out percentage rather than the savings half alone.
• Cumulative cost no longer mispriced. A Task sub-agent's usage is the total summed across its entire run; pricing it as a single turn produced inflated four-figure per-event costs that poisoned FinOps aggregates. Task usage is now tagged usage_scope: "task_cumulative" and is not priced per-turn; per-turn cost comes only from per-turn signals.

All changes are additive and backward compatible.