v0.19.0 shipped V4 to V6 with value-noise grain, so those stay frozen and
the crystal grain becomes a process of its own. V7 is V6 plus the grain:
without grain it renders as V6 (`without_grain_v7_renders_as_v6`), and the
GPU equivalence cases now cover V6's value noise.
Merged with main's float output (`deep`, `hdr`): the value noise keeps its
clamped luminance; the crystal grain already clamps, and fades out at and
above SDR white. The finish kernel's failed-render check stays ahead of
the aux upload.
The test of unknown process numbers now takes one past the latest: 7 was
hard-coded, and is a known process now.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>