Bugfixes 1-7-2026

[SchoolyB]

Summary

Collection of bug fixes from January 7, 2026.

Included Fixes

fix(interpreter): allow arbitrary precision arithmetic for int/uint types (#917)

• The int and uint types are backed by big.Int but arithmetic operations were incorrectly capping at i64/u64 bounds
• Now these types have no overflow limits, matching their arbitrary precision storage

fix(typechecker): show correct error for invalid sized types with using directive (#914)

• When a using directive was present, undefined types like i512 showed "type mismatch" instead of "undefined type"
• Added check to detect invalid sized type patterns and reject them before deferring to module resolution

fix(parser): error on invalid operators in string interpolation (#916)

• String interpolation was silently dropping expressions with invalid operators (&, |, ^)
• Now checks for lexer errors and unconsumed tokens after parsing interpolated expressions

Test plan

• All individual PRs tested and merged
• All existing tests pass