feat(math): 3D Math Extension — Quaternion (RF5.1)

[LyeZinho]

Summary

Extensão da biblioteca matemática da Fase 1 com Quaternion para rotações 3D. Implementa operações completas de quaternions: construção (axis-angle, Euler, lookAt, matrix), interpolação (SLERP/NLERP), conversões (toEuler, toMatrix), e rotação de vetores.

📦 Files Created

• src/math/Quat.hpp — Full Quaternion struct with 24 inline methods:
  • fromAxisAngle, fromEuler, lookAt, fromMatrix — constructors
  • slerp, nlerp — spherical & normalized linear interpolation
  • toEuler, toMatrix — conversions
  • rotate, conjugate, inverse, normalized, length — operations
  • operator* — Quat composition & vector rotation
  • Follows existing Caffeine namespace (same as Vec3, Mat4)

🔧 Files Modified

• src/math/Math.hpp — Added PI_HALF constant
• src/Caffeine.hpp — Included Quat.hpp
• tests/test_math.cpp — 24 test cases covering all Quat operations
• docs/fase5/3d-math.md — Updated status to ✅ Implementado

✅ Acceptance Criteria

• Quat::slerp produces correct interpolation between any two orientations
• quat.toMatrix() produces same matrix as Mat4::fromAxisAngle
• Quat * Vec3 rotates correctly
• No gimbal lock in composed 3-axis rotations
• Vec4 aligned to 16 bytes (Fase 1 — unchanged)
• All float comparisons use Approx().epsilon(0.001f)

🧪 Tests (24 cases)

Identity, axis-angle, Euler, composition, vector rotation, conjugate, inverse, normalization, SLERP, NLERP, matrix conversion, lookAt, roundtrip conversion.