fix: transaction execution when accountOverride is present for postquote transaction

[jpuri]

Explanation

In case of postquote transaction with accountOverride add delegation to execute quote on behalf of the override account.

References

Related to https://consensyssoftware.atlassian.net/browse/CONF-1323

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

---

Note

Medium Risk
Changes the Relay post-quote submission path to swap a prepended original tx for a delegation tx when accountOverride is used, affecting how batched transactions are constructed and submitted. Incorrect delegation construction or account-detection could break post-quote execution for overridden accounts.

Overview
Fixes Relay post-quote submission when accountOverride is present by detecting from divergence and replacing the prepended original transaction with a delegation transaction built via TransactionPayController:getDelegationTransaction.

Adds buildDelegatedOriginalParams to fetch and inject the delegation tx params, updates batching logic accordingly, and extends relay-submit.test.ts with coverage ensuring the delegation is requested/used only when an override is set. Updates the package changelog to document the fix.

^{Reviewed by Cursor Bugbot for commit f93b79e. Bugbot is set up for automated code reviews on this repo. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 60a7c68. Configure here.}