fix[lang]: preserve ABI metadata in array types

[DicksonWu654]

What I did

Preserve ABI metadata while recursively decoding fixed-size array types. This
prevents ABI entries for decimal arrays from being reconstructed as int168
arrays.

How I did it

Array decoding now carries the original ABI dictionary into the recursive
base-type call while replacing only the type field. This retains
internalType: decimal through every array dimension. Unit tests cover
one- and two-dimensional decoding, the int168 fallback, and a complete
compile/ABI/reconstruction round trip.

How to verify it

$ uv run pytest -q tests/unit/semantics/types
1435 passed, 2 warnings

$ uv run make lint
Success: no issues found in 206 source files
All done! ✨ 🍰 ✨
637 files left unchanged.
Skipped 2 files

Commit message

Array type parsing rebuilt the ABI description using only its type string.
This discarded internalType before parsing the base type, so decimal arrays
were reconstructed as int168 arrays even though scalar decimals were handled
correctly.

Carry the original ABI metadata through recursive array parsing. This
preserves the decimal distinction at every array depth while retaining the
existing int168 fallback when internalType is absent.

Description for the changelog

Fix ABI round trips incorrectly reconstructing decimal array elements as
int168.

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[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-12T02:08:34.502559Z	2a8fceb	PR opened

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