Collect batch fees into the builder wallet

[Mirko-von-Leipzig]

Summary

The sequencer runs batch fee collection as an independent task. Each collection reads the public wallet and its unspent P2ID notes from the store, then submits an ordinary sealed transaction through the in-process RPC to consume those notes into the wallet.

The collection interval defaults to five minutes and is configurable through --batch.builder.wallet-sync-interval. Transactions respect the protocol input-note limit and include a fee note even when fees are zero.

Each transaction expires after 30 blocks. The task waits for expiration before another collection, including when submission reports an error. Each collection reads fresh chain state, so no separate account database is required.

Transaction execution runs on a blocking worker. Proving is delegated to the remote transaction prover configured with --tx-prover.url.

Part of #2501.

Changelog

[[entry]]
scope       = "node"
impact      = "added"
description = "Periodically collect batch-building fee notes into the public builder wallet."