Color: Project Settings ▸ Working Gamma 2.2 / 2.4 with no working space, as in After Effects (#495)

After Effects' `app.project.workingGamma` (2.2 or 2.4, ignored with a working space) sets
the curve an unmanaged project uses: at 2.2 the piecewise sRGB curve, at 2.4 a pure 2.4
power curve. EffectCraft always used sRGB, so linear EXRs (Interpret As Linear Light) from
a 2.4 project came out darker in the shadows (0.18 → 0.461 instead of 0.490).

- `ProjectSettings::working_gamma` (default 2.2, serde default for old projects).
- The colour pipe's unmanaged curve is the Working Gamma's (sRGB, or Rec. 709's pure 2.4
  curve): Interpret As Linear Light encodes untagged footage with it and Blend Colors Using
  1.0 Gamma linearizes with it; it is part of the pipe's cache key. The GPU path takes the
  same conversions.
- `file.projectSettings {workingGamma: 2.2|2.4}` (other values are refused, as in AE),
  `app.project.workingGamma` in scripts and a Working gamma choice in Project Settings.

Test: render test with linear 0.051 / 0.18 / 0.5 footage (0.290 / 0.490 / 0.749 at 2.4,
0.250 / 0.461 / 0.735 at 2.2, the values measured in AE), linear blending at 2.4, a working
space ignoring the setting, and the cache key.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QiAJeFttZp83Fh7YuzAR5f

crates/script/src/model.rs

@@ -82,6 +82,7 @@ fn project(s: &Session) -> J {
         "linearBlending": p.settings.blend_linear,
         "linearizeWorkingSpace": p.settings.linearize,
         "workingSpace": p.settings.working_space.map(|w| format!("{w:?}")).unwrap_or_default(),
+        "workingGamma": if p.settings.working_gamma_24() { 2.4 } else { 2.2 },
         "timeDisplayFrames": p.settings.time_display == effectcraft_project::TimeDisplayStyle::Frames,
         "renderQueue": p.render_queue.len(),
         "revision": s.revision,

crates/script/src/prelude.js

@@ -1696,6 +1696,8 @@ Project.prototype = {
   set linearizeWorkingSpace(v) { __call("file.projectSettings", { linearize: !!v }); },
   get workingSpace() { return this.__info().workingSpace; },
   set workingSpace(v) { __call("file.projectSettings", { workingSpace: String(v) || "none" }); },
+  get workingGamma() { return this.__info().workingGamma; },
+  set workingGamma(v) { __call("file.projectSettings", { workingGamma: __num(v) }); },
   get timeDisplayType() { return this.__info().timeDisplayFrames ? TimeDisplayType.FRAMES : TimeDisplayType.TIMECODE; },
   set timeDisplayType(v) { __call("file.projectSettings", { timeDisplay: v === TimeDisplayType.FRAMES ? "frames" : "timecode" }); },
   get expressionEngine() { return "javascript-1.0"; },