V1 transactions: release plan

[mcintyre94]

We should now have in Kit full end-to-end support for v1 transactions: manipulate config, compile, encode/decode, decompile.

This issue is to track what we need to land this feature:

• End-to-end testing, including using a build of Agave that can process v1 transactions
• Update the type of createTransactionMessage to support { version: 1 }
• Docs, probably a new guide in Kit from our side
• A changeset with documentation of the new API to set config
• Timing: do we sync with the first Agave release that supports v1, or ship our support independently/ahead? Ideally we're no later than Agave v1 on testnet.

Other things to update:

• Does RPC shape of getTransaction change at all with json/jsonParsed encoding? Asked on Discord
• kit-plugins default executor to support v1. Probably makes sense to drop the compute-budget client dependency (for v1) and just have the executor simulate and update config values. Need to move some code into Kit for the core simulate/extract values.
• nice to have: Explorer support. Claude analysis/plan to use Kit on the transaction view: https://github.com/mcintyre94/explorer/blob/8c03a6e869a9168725c3e30d4f3caebc40813c40/docs/transaction-view-kit-migration.md

We also independently have support for larger transactions after/alongside v1 (only supported for v1), which mostly depends on a solution for #1223.