Verify Token-2022 settlement against the relevant test suite wholistically

[kaze-cow]

Add a macro to run any token-moving tests against both SPL token and Token 2022.

Stacked on #120.

Approach

The Token-2022 paths in #120 are worth little if they only hold for the handful of cases someone thought to write twice. So rather than a parallel Token-2022 suite, this reruns the suite that already exists against the second program.

common::also_under_token_2022!(some_test) sits in front of a test and generates some_test_token_2022, which runs the same body with Token-2022 as the thread-local active program:

common::also_under_token_2022!(settles_a_single_order);
#[test]
fn settles_a_single_order() { .. }

The body of the function can be used as is. The token helpers in tests/common/token.rs build against the program that owns the account they are handed (token::program_of), and payer_signed_tx / signed_tx repoint the legacy program id in every instruction they assemble.

A regular macro with pastey was used instead of a proc_macro to reduce the weight and maintenance that comes with needing to write an entire program to execute a macro. The only major downside I see with this approach is that the test name needs to be repeated in the macro parameters.

The max_buffers* tests were also included in this. In the case of CreateBuffers, we hit the CPI token account limit, so the limit is actually lower there.

Compute cost

bench-report.json gains readings for every generated test. Token-2022 costs more per instruction, as expected from the longer accounts and the extension-aware transfer path — e.g. settle/settles_multiple_orders 23,257 → 27,350 CU, create_buffers/happy_path_creates_initialized_buffer_token_account 10,361 → 11,695 CU. Transaction bytes and account counts are identical between the two.

Verification

Verify the approach. Confirm new tests are generating benchmarks and behavior as expected.

There may be cases where other non-generated tests are needed specific to token2022. If so, please say!

🤖 Generated with Claude Code

[linear-code]

SC-153

[kaze-cow]

add an extension for metadata to ensure we have full token2022 situational coverage

also double check that test suggestions from base pr have been addressed.