SimSat v0.1.5 - brighter land and natural domain-edge clouds

SimSat v0.1.5 improves visible-satellite land brightness and makes clouds fade naturally at exposed finite-domain boundaries across WRF and HRRR inputs.

Highlights:

• A reviewed visible default exposure of 1.5, replacing the systematically dark surface presentation while retaining explicit overrides.
• Surface solar-zenith normalization and a bounded dark-land toe are enabled by default, improving low-sun land visibility without lifting ocean or cloud radiance.
• Exposed-domain cloud-edge feathering is enabled by default, replacing hard rectangular cloud cutoffs with a controlled fade only where the camera can see beyond the finite model domain.
• Matching controls in the Rust API, headless CLI, Python binding, and SimSat Studio. Every new appearance operator can be disabled to recover the legacy path.
• CPU and GPU implementations of the new land operators are parity-tested. Studio preserves existing saved calibrations and offers the v0.1.5 preset explicitly.
• Faster preparation for surface-only/cloud-disabled renders plus a parallel multi-case QA runner for cross-file calibration.

The higher-order delta-flux cloud-transport experiment shown in the local QA matrix is intentionally not part of this release; it remains an opt-in v0.1.6 candidate pending broader case review.

The Windows executable is unsigned because the project signing certificate has expired. If Microsoft Defender SmartScreen appears, choose More info, then Run anyway, and verify the SHA-256 checksum before launching.

SHA-256 checksums:

• simsat-studio-v0.1.5-windows-x86_64.exe:
  CB6FE6343FAC5FF677782C5B068765F8EB4E9BFA6393BE56E568CCC6F8255253
• simsat-0.1.5-cp38-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl:
  7A3FAA13E1248F50887ACC9C0CB47348FA93FEF5773F7BA0D491ADE5B2064939
• simsat-cli-v0.1.5-linux-x86_64.tar.gz:
  0B310DEF0AA7CE71E6C32CFBFB63391BE31DBC3C4431F026F23315E003E1AB3A
• THIRD-PARTY-NOTICES.txt:
  301F4041951145FCD822A9CECC1A29730ABC7710C081E39F0FD07D6CAF6D3419