v0.5.4: temporal-samples default fix

v0.5.4 fixes a temporal-samples default that made the named quality tiers (Draft, Standard, High) slower than necessary.

Changed

• Named tiers default to single-pass rendering. The "use genome default" fallback for temporal-samples=1 now applies only to genome-default quality (the mastering path, byte-identical to animate). For the named tiers, temporal-samples=1 is literal single-pass. This removes the dispatch overhead of about 64 sub-passes at low samples-per-pixel (measured +136% at spp 8, +35% at spp 30) for within-frame motion blur that is invisible on slow loops. Users can still raise temporal-samples explicitly for motion blur.
• The export sheet label reflects this ("single-pass" for named tiers, "genome default" for genome-default).

Notes

• Genome-default quality is unchanged (byte-identical to animate). animate/export byte-identity and Metal/CPU parity are preserved.
• Temporal samples is motion blur, not grain; it does not affect the noise level (grain scales with samples-per-pixel).

Install
Download and unzip. The binary is unsigned, so clear quarantine before running:
xattr -dr com.apple.quarantine emberweft emberweft_FlameRenderer.bundle
Run the GUI from the folder that holds the resource bundles:
./emberweft-gui
Or the CLI:
./emberweft --help
Requires macOS 26 on Apple Silicon.