Default EnvironmentProbe SH baking to FAST and remove AUTO mode

[Copilot]

QUALITY SH baking is unstable on macOS when using ANGLE/Metal, and AUTO could still route into problematic behavior depending on platform logic. This update removes AUTO entirely and makes FAST the default SH baking path.

• Mode model simplification (AUTO removed)

  • Removed SphericalHarmonicsMode.AUTO from IBLGLEnvBakerLight.
  • Removed OS-based AUTO branching in SH bake path.
  • Kept explicit FAST and QUALITY behavior unchanged.

• Default behavior change to FAST

  • Updated IBLGLEnvBakerLight default SH mode to FAST.
  • Updated EnvironmentProbeControl default SH mode to FAST.
  • Updated serialized default in EnvironmentProbeControl.write(...) to FAST.

• Backward compatibility for serialized data

  • Added compatibility mapping in EnvironmentProbeControl.read(...) so legacy serialized mode values (including "AUTO") resolve to FAST instead of failing or requiring AUTO to exist.

public enum SphericalHarmonicsMode {
    FAST,
    QUALITY
}

[!WARNING]

[riccardobl]

@copilot remove this test, it is useless

[Copilot]

Addressed in commit 9c403a9: removed jme3-core/src/test/java/com/jme3/environment/EnvironmentProbeControlTest.java.