feat(engine): clip move, clip effect_input, mandatory static FFmpeg

- oakengine_sequence_move_clip implemented for real (oaktimeline
  TrackMoveBlockCommand; fixes the graph-ownership/gap-anchor/ripple
  trim bugs the stub was hiding); same-track via the frozen C ABI,
  cross-track supported by the module command
- oaknode clip blocks now declare a tex_in texture input and set
  effect_input to it, so timeline clips can host effect chains; facade
  test covers effect insert/remove on a real clip
- oakffmpeg-link: FFMPEG_DIR is now mandatory with a clear panic (a
  Homebrew upgrade left the system ffmpeg .pc pointing at a deleted
  dav1d Cellar path, breaking links); reads a git-ignored workspace
  .env for IDEs that cannot inject env vars (RustRover); links the C++
  stdlib for C++ codec libs (svt-av1)
- oakengine re-exports oaknode so tests share one crate instance;
  it_node uses the direct instance's value type where it calls the
  module FFI (the --workspace dev-dependency feature split builds
  oaknode twice)

crates/oaknode/src/ops.rs

@@ -63,7 +63,11 @@ pub fn copy_inputs(
 	// C++ copies per-element too — array elements are covered when the
 	// array family lands).
 	for id in &src_inputs {
-		if !graph.get(dst).map(|e| e.core.has_input(id)).unwrap_or(false) {
+		if !graph
+			.get(dst)
+			.map(|e| e.core.has_input(id))
+			.unwrap_or(false)
+		{
 			continue;
 		}
 		let value = {
@@ -72,16 +76,16 @@ pub fn copy_inputs(
 		};
 		let declared = {
 			let entry = graph.get(src).ok_or(Error::NotFound)?;
-			entry.core.input_data_type(id).unwrap_or(crate::value::ValueType::None)
+			entry
+				.core
+				.input_data_type(id)
+				.unwrap_or(crate::value::ValueType::None)
 		};
 		let value = {
 			// Re-quantize to the destination's declared type so the copy
 			// never stores a mismatched payload.
 			let entry = graph.get(dst).ok_or(Error::NotFound)?;
-			let dst_declared = entry
-				.core
-				.input_data_type(id)
-				.ok_or(Error::NotFound)?;
+			let dst_declared = entry.core.input_data_type(id).ok_or(Error::NotFound)?;
 			if dst_declared == declared {
 				value
 			} else {
@@ -294,8 +298,7 @@ pub fn set_value_at_time_command(
 			move || {
 				let mut g = lock_any(&project_undo);
 				if let Some(e) = g.graph.get_mut(node) {
-					e.core
-						.set_standard_value(&input_undo, element, old.clone());
+					e.core.set_standard_value(&input_undo, element, old.clone());
 				}
 			},
 		)