fix(core): prevent overflow in range and capture checks

[bobzhang]

Large offsets, lengths, and capture indices can overflow signed Int arithmetic and bypass range checks. For example, [1, 2].chunks(2147483647) returns an empty array, and an overflowing regex group index can resolve to group 0.

Use subtraction-based bounds checks for byte copies and Deque ranges, overflow-safe chunk calculations, and validation before multiplying capture indices. Add regression cases for overflowing inputs and valid empty ranges.

Validation:

• moon check --deny-warn
• moon test builtin deque string --target all
• moon info; generated interfaces unchanged

[coveralls]

Coverage Report for CI Build 6621

Coverage remained the same at 89.314%

Details

• Coverage remained the same as the base build.
• Patch coverage: 5 of 5 lines across 4 files are fully covered (100%).
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	18408
Covered Lines:	16441
Line Coverage:	89.31%
Coverage Strength:	280806.47 hits per line

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💛 - Coveralls