* txpool: drop interop transactions on reorg and head reset

Interop executing messages (targeting CrossL2InboxAddress) depend on
cross-chain state that may be invalidated by reorgs or head resets.

Two eviction paths, both gated on len(pool.ingressFilters) > 0:

1. Reinjection filter: when discarded blocks are walked during a normal
   reorg, filterInteropTxs removes interop txs from the reinject set.

2. Pool-wide eviction: after every head reset (including setHead-style
   rewinds from ForkchoiceUpdated), all interop txs are eagerly removed
   from the pool. This covers the case where old blocks are pruned and
   the reinjection path is skipped.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* txpool: upgrade interop reorg drop log to Warn

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: opsuperchain <opsuperchain@slop.bot>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>