[bhelm]

What this PR does

Defines one cross-platform integer rounding rule for Charge driver marginal points: nearest, with exact half-ties away from zero. Kotlin now matches the existing Swift behavior for negative half-ties, while the Recovery score and all other driver fields remain unchanged.

Type of change

• Bug fix
• New feature
• Refactor / cleanup
• Documentation
• CI / tooling

How it was tested

• RED: focused Android RecoveryDriversTest ran 9 tests with exactly 2 expected failures before the fix: the negative -0.5 boundary and the real issue reproduction through the default eighth argument.
• Swift oracle/control: focused ChargeDriversTests passed 14/14 before the Kotlin fix.
• GREEN on the clean upstream branch: focused Swift ChargeDriversTests passed 14/14; the three established Linux compatibility gates were applied only for the run and fully reverted afterward.
• GREEN on the clean upstream branch: focused Android RecoveryDriversTest passed 9/9 with JDK 17, one worker, no parallel Gradle execution, and the Kotlin compiler in-process.
• Mirrored tests pin -0.5, +0.5, neighboring non-ties, the exact seven-argument/default-arg8 reproduction, unchanged Recovery score, and the complete driver row.

Checklist

• Swift package tests pass for any package I touched (swift test in Packages/<name>)
• Android unit tests pass if I touched android/ (./gradlew testFullDebugUnitTest)
• No new build warnings introduced
• UI changes use only StrandDesign tokens — no UI changes
• No hardcoded hex frame bytes; no protocol changes
• Follows the conventions in docs/CONTRIBUTING.md
• I did not commit generated output or secrets/keystores

The two full-suite checklist items remain unchecked because this bounded fix ran the requested focused native regression suites.

Related issues

Fork issue: bhelm#51