[YugShah1510]

Summary

• Validate INT64 inputs with RapidJSON IsInt64() and UINT64 inputs with IsUint64() before reading their 64-bit values.
• Add regression coverage for values above the 32-bit signed and unsigned ranges.

Fixes #4688

Validation

• git diff --check — passed.
• The targeted OVMS C++ parser tests were not run: Bazel/Bazelisk and a built ovms_test binary are unavailable in this environment.

[Copilot]

🟢 Approval recommended

The narrow validation changes correctly match the existing getters, and regression tests cover both reported failures with no blocking issues identified.

No open issues 🎉

What changed in this PR

Fixes #4688 by allowing KServe REST inputs to accept 64-bit integers beyond the corresponding 32-bit ranges.

Changes:

• Uses IsInt64() and IsUint64() to match the existing 64-bit getters.
• Adds regression tests that verify acceptance and value preservation for both reported failures.

The targeted C++ tests were not run because the required build tools and test binary were unavailable.

File	Description
src/​test/​kfs_rest_parser_test.cpp	Adds signed and unsigned regression cases above the 32-bit limits.
src/​rest_parser.cpp	Corrects validation checks for INT64 and UINT64 inputs.

_{Review effort: Balanced}