[L0STE]

LiteSVM meters a transaction's loaded accounts data size against its limit (SIMD-0186), but it misses one rule Agave applies, and it doesn't tell the caller the size it metered.

Count programdata (fix). Agave also counts the programdata of every loader-v3 program the transaction loads: 64 bytes plus its data, once, and not at all when the transaction lists the programdata account itself (account_loader.rs#L543-L563). LiteSVM skipped it, so any transaction touching an upgradeable program (every Anchor program) was metered below what mainnet counts. A transaction that sets set_loaded_accounts_data_size_limit from a LiteSVM run could then pass here and fail on mainnet with MaxLoadedAccountsDataSizeExceeded.

Return the size (feature). TransactionMetadata gains loaded_accounts_data_size, set by send_transaction and simulate_transaction, including for transactions that fail in execution. RPC layers built on LiteSVM, like Surfpool's simulateTransaction, can report it instead of recounting it themselves.

Notes:

• It is a new public field on TransactionMetadata, so code that builds the struct with a literal needs to set it.
• litesvm-persistence doesn't store the field, so the snapshot format is unchanged and restored history reports 0. Happy to persist it with a format version bump instead, if you prefer that.

Tests, in tests/compute_budget.rs:

• test_loaded_accounts_data_size_counts_programdata: with an upgradeable program in the transaction, a limit at the exact size passes and one byte below fails, both when the programdata is unlisted (counted with the program) and when it is listed (counted once).
• test_transaction_metadata_reports_loaded_accounts_data_size: the reported size equals the metered size for a simulated, a successful and an execution-failed transaction.

cargo test --features precompiles, cargo clippy --all-targets -- -D warnings (with and without --all-features) and cargo +nightly fmt --all -- --check pass.