fix: correct progress for one-sided ranges

[gooddev97]

Summary

• Compute ring progress relative to zero clamped into the configured range.
• Prevent positive-only and negative-only ranges from showing a half-filled ring at their neutral endpoint.
• Add regression coverage for both one-sided range directions.

Verification

• bun run lint
• bun run typecheck
• bun run test (23 tests pass)
• bun run build
• bun run pack:check
• Real-device visual check

Compatibility

• Platform(s): iOS and Android
• React Native version: 0.86.3 in the example app; public peer range >=0.81.0 <0.87
• Expo version or bare React Native: Expo SDK 57
• Dial Slider/Reanimated/Worklets/Gesture Handler/SVG/Linear Gradient versions: 0.1.0 / 4.5.1 / 0.10.1 / 2.32.x / 15.15.4 / 57.0.1

Contributor checklist

• I added or updated regression tests for behavior changes and bug fixes.
• Public API documentation and examples do not need changes for this internal math fix.
• I kept generated lib output out of the commit.
• I did not include secrets, credentials, or private user data.
• No breaking change or migration is required.

[ngocdevv]

Approved after successful automated verification.