Skip building invariant delta when no invariants are enabled.

[dmkozh]

Description

Skip building invariant delta when no invariants are enabled.

The delta is only used for invariants, so also updated the naming to reflect that.

Checklist

• Reviewed the contributing document
• Rebased on top of master (no merge commits)
• Ran clang-format v8.0.0 (via make format or the Visual Studio extension)
• Compiles
• Ran all tests
• If change impacts performance, include supporting evidence per the performance document

[Copilot]

Pull request overview

This PR optimizes parallel Soroban transaction application by skipping construction of the ledger-entry delta used for invariant checking when no invariants are configured/enabled, and renames related APIs to make the delta’s purpose explicit.

Changes:

• Guard delta construction in TransactionFrame::parallelApply behind a new Config::invariantsEnabled() helper.
• Rename TxEffects/parallel-apply delta APIs to clarify they exist specifically for invariants.
• Skip checkAllTxBundleInvariants entirely when invariants are disabled, and relocate refundable-fee meta setting accordingly.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/transactions/TransactionFrame.cpp	Avoids building invariant-only deltas when invariants are disabled.
src/transactions/ParallelApplyUtils.h	Renames thread-state helper to reflect invariant-specific delta.
src/transactions/ParallelApplyUtils.cpp	Updates delta construction to write into invariant-specific delta storage.
src/transactions/ParallelApplyStage.h	Renames TxEffects delta storage/accessors to invariant-specific names.
src/main/Config.h	Adds Config::invariantsEnabled() API.
src/main/Config.cpp	Implements Config::invariantsEnabled() based on INVARIANT_CHECKS.
src/ledger/LedgerManagerImpl.cpp	Skips invariant checks when disabled; updates delta accessor usage; adjusts refundable-fee meta placement.