Description

Adds a per-transaction EIP-7825 gas cap check to GenerateNUTBundle._assertValidOutput. Any NUT bundle transaction whose gasLimit exceeds the Osaka cap (2**24 = 16_777_216) is now rejected at bundle-generation time rather than at execution.

The EIP-7623 calldata floor check already landed in #20075. This PR folds it together with the new upper cap into a single bounded-range require:

• Lower bound: EIP-7623 calldata floor (UpgradeUtils.computeFloorDataGas).
• Upper bound: EIP-7825 per-tx cap (MAX_TX_GAS_LIMIT = 2**24).

Also refactors GenerateNUTBundle to separate orchestration from bundle construction so tests can validate bundles without writing the artifact:

• run() runs setUp, then _buildOutput, then _assertValidOutput, then writeArtifact.
• _buildOutput() builds the Output struct with no disk I/O.
• _assertValidOutput() performs all validation checks.

A GenerateNUTBundle_Harness test contract exposes buildOutput() and assertValidOutput() externally. This lets fuzz iterations validate bundles without racing on CURRENT_BUNDLE_PATH.

Tests

Full negative-path coverage for every branch in _assertValidOutput was added to test/scripts/GenerateNUTBundle.t.sol. Each test follows the same pattern:

• Invoke script.buildOutput() (harness) to produce a valid bundle
• Mutate a single field (or the array length)
• Assert that script.assertValidOutput reverts with the expected error message

Cases covered:

• Transaction count mismatch
• Empty data
• Empty intent
• Zero to
• gasLimit above the EIP-7825 cap
• gasLimit of zero (rejected by the floor)
• gasLimit one below the EIP-7623 floor
• Zero from paired with a non-privileged to

The count-mismatch test uses assembly to rewrite the in-memory array length rather than rebuilding the array. Shrink-only, because growing would blow up the ABI encoding on the external call to assertValidOutput.

Additional context

Issue #20109 calls for two checks: the EIP-7825 upper cap and an op-geth EIP-7623 floor. The floor portion was resolved by #20075. This PR adds the remaining cap check and consolidates the two into one range check.

Metadata

Closes #20109