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, 23 insertions, 0 deletions

diff --git a/rust/crates/animation/src/path.rs b/rust/crates/animation/src/path.rs
new file mode 100644
index 00000000..56256c61
--- /dev/null
+++ b/rust/crates/animation/src/path.rs
@@ -0,0 +1,23 @@
+use crate::effect_param_channel::is_effect_param_path;
+use crate::graphic_param_channel::is_graphic_param_path;
+use crate::property_groups::is_animation_property_path;
+
+pub fn is_animation_path(property_path: &str) -> bool {
+    is_animation_property_path(property_path)
+        || is_graphic_param_path(property_path)
+        || is_effect_param_path(property_path)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn classifies_animation_paths() {
+        assert!(is_animation_path("opacity"));
+        assert!(is_animation_path("params.blur"));
+        assert!(is_animation_path("effects.glow.params.intensity"));
+        assert!(!is_animation_path("transform"));
+        assert!(!is_animation_path("bindings"));
+    }
+}