* fix(agents,failover): propagate sessionId/lane/provider attribution through FailoverError
Adds optional `sessionId` and `lane` fields to `FailoverError` and threads
them — together with the existing `provider`, `model`, `profileId` — through
`describeFailoverError` and `coerceToFailoverError` context, so structured
error log ingestion can attribute exhausted-fallback wrapper errors back
to the originating request instead of dropping the per-profile metadata
when the final wrapper is built.
Fixes#42713.
* fix: preserve failover error attribution
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Co-authored-by: Altay <altay@uinaf.dev>
9df0ae6767