[andrewtdiz]

Summary

• add a generator FinallyRoute for non-yielding try/finally regions and split those finalizers into explicit state-machine states
• run active pending finalizers from .return() and no-catch .throw() before completing/rethrowing
• resume catch routes through same-try finalizers so caught .throw() continues to the next suspension point
• add regression coverage for nested finalizers and finalizer return superseding abrupt completion

Refs #4374

Validation

• cargo check -p perry-transform
• cargo build --release --quiet -p perry -p perry-runtime -p perry-stdlib
• tests/test_issue_4374_generator_abrupt_finally.sh
• tests/test_issue_4036_async_try_catch_after_await.sh
• bash tests/test_issue_3583_async_semantic_parity.sh
• cargo fmt --all -- --check
• git diff --check
• ./scripts/check_file_size.sh
• focused Node 26/Perry repro comparison for generator .return() and .throw() through pending finally

[proggeramlug]

Superseded by #4383 (fix for #4374, run pending try/finally on .return()/.throw() abrupt completion), already merged to main. Both rewrite generator/linearize.rs + lower.rs for the same abrupt-completion-finally behavior. Closing as duplicate.