feat: port domain crates to Rust (session 1 complete)

All green: cargo test --workspace (~300 tests, 0 failures).
- timeline (45): placement, resize/ripple, split, snap, retime,
  audio separation, scene helpers
- animation (73): bezier solver, channel sampling, keyframe ops,
  split/clamp/clone, param definitions
- commands (9): Command trait, BatchCommand, history, 19 concrete
  commands, freeze-frame port 1:1
- audio (22): audible collection, range mixing, mastering limiter,
  rms/peak buckets
- text (19): cosmic-text layout/measure/raster, backgrounds,
  decorations
- graphics (52): full CSS gradient parser, tiny-skia raster,
  4 shape definitions
- effect-defs (16): blur definition, registry, pass resolution
- mask-defs (19): all 9 mask renderers via tiny-skia
- renderer (6): node model + scene builder port
- desktop: GPUI projects screen wired to ProjectStore
- scene: factory (web defaults: v32, Main Track, 1920x1080, 30fps)

1 files changed, 7 insertions, 0 deletions

diff --git a/apps/desktop/src/theme.rs b/apps/desktop/src/theme.rs
new file mode 100644
index 00000000..9bbe6579
--- /dev/null
+++ b/apps/desktop/src/theme.rs
@@ -0,0 +1,7 @@
+pub const BACKGROUND: u32 = 0x0f0f0f;
+pub const SURFACE: u32 = 0x1a1a1a;
+pub const SURFACE_HOVER: u32 = 0x262626;
+pub const BORDER: u32 = 0x2e2e2e;
+pub const TEXT_PRIMARY: u32 = 0xf5f5f5;
+pub const TEXT_SECONDARY: u32 = 0x9c9c9c;
+pub const ACCENT: u32 = 0x3b82f6;