After every generate run, compute variance between the executing plan
snapshot and the just-recorded usage rollup, persist it to
output/budget/summary.yaml (overwrite-on-run), and surface it both in
the generate status JSON (new budget_summary field) and as a "Plan
variance" line in reports/generation-summary.md.
Variance fields: calls / prompt_tokens / total_tokens each carry
{estimated, actual, delta, ratio}; cost_usd carries {estimated,
actual_known, actual_estimated_from_rates, actual_total, delta, ratio};
per_workflow rolls the per-bucket usage up to the same workflow_id grain
the plan reports. Runs whose snapshot_id cannot be resolved (no prior
plan, or pruned from the retention window) still record a variance row
with null comparison fields and snapshot_resolved=false, so the
consumer always sees a current summary.
Reordered run_generation so usage and variance are written before the
generation report, allowing the report to embed the variance line on
the same pass.
110 tests pass.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
tegwick
d4c9c56f5c