Include paid failures when reconstructing request costs

When reconstructing a workflow's API cost, reconcile all provider attempts rather than only saved successful results. A local timeout can occur after the provider generated billable output, and a successful fallback can hide the first charge from application traces. Link provider receipts to attempt identifiers whenever possible; without them, label temporal assignments as inferred and keep unmatched usage unresolved. A successful retry does not establish that the earlier attempt was free. A rate-verification canary confirms pricing but cannot recover missing historical usage.

Applies when: A workflow retries or falls back after a provider error. Keywords: billing timeout fallback retry provider receipt attempt reconciliation