feat: GPUI desktop port foundation

- scene crate: full project/scene/element model, serde round-trip
  proven against the web SerializedProject shape
- transfer crate: .ocp zip container, cross-compat with web fflate
  archives proven in both directions
- storage crate: filesystem project store replacing IndexedDB,
  .ocp import/export
- media crate: ffmpeg-next 8 decoder (frames, audio, thumbnails,
  waveform summaries)
- playback crate: wall-clock anchored, frame-rounded playback clock
- gpu crate: native texture readback; compositor renders headless
  offscreen on Vulkan (spike test)
- flake devshell: rust toolchain, GPUI native deps, ffmpeg dev,
  bindgen clang args; GPUI hello-world builds
- port plan in notes/gpui-port.md

8 files changed, 381 insertions, 0 deletions

diff --git a/rust/crates/commands/src/scene/create_scene.rs b/rust/crates/commands/src/scene/create_scene.rs
new file mode 100644
index 00000000..1f2de02b
--- /dev/null
+++ b/rust/crates/commands/src/scene/create_scene.rs
@@ -0,0 +1,46 @@
+use scene::{Project, Scene};
+
+use crate::command::{Command, CommandError, CommandResult};
+
+pub struct CreateSceneCommand {
+    name: String,
+    is_main: bool,
+    saved_scenes: Option<Vec<Scene>>,
+    created_scene_id: Option<String>,
+}
+
+impl CreateSceneCommand {
+    pub fn new(name: impl Into<String>, is_main: bool) -> Self {
+        Self {
+            name: name.into(),
+            is_main,
+            saved_scenes: None,
+            created_scene_id: None,
+        }
+    }
+
+    pub fn scene_id(&self) -> Option<&str> {
+        self.created_scene_id.as_deref()
+    }
+}
+
+impl Command for CreateSceneCommand {
+    fn execute(
+        &mut self,
+        project: &mut Project,
+    ) -> Result<Option<CommandResult>, CommandError> {
+        self.saved_scenes = Some(project.scenes.clone());
+
+        let created = timeline::scenes::build_default_scene(&self.name, self.is_main);
+        self.created_scene_id = Some(created.id.clone());
+        project.scenes.push(created);
+        Ok(None)
+    }
+
+    fn undo(&mut self, project: &mut Project) {
+        let Some(saved) = &self.saved_scenes else {
+            return;
+        };
+        project.scenes = saved.clone();
+    }
+}
diff --git a/rust/crates/commands/src/scene/delete_scene.rs b/rust/crates/commands/src/scene/delete_scene.rs
new file mode 100644
index 00000000..61763dfd
--- /dev/null
+++ b/rust/crates/commands/src/scene/delete_scene.rs
@@ -0,0 +1,61 @@
+use scene::{Project, Scene};
+
+use crate::command::{Command, CommandError, CommandResult};
+
+pub struct DeleteSceneCommand {
+    scene_id: String,
+    saved_scenes: Option<Vec<Scene>>,
+    saved_current_scene_id: Option<String>,
+}
+
+impl DeleteSceneCommand {
+    pub fn new(scene_id: impl Into<String>) -> Self {
+        Self {
+            scene_id: scene_id.into(),
+            saved_scenes: None,
+            saved_current_scene_id: None,
+        }
+    }
+}
+
+impl Command for DeleteSceneCommand {
+    fn execute(
+        &mut self,
+        project: &mut Project,
+    ) -> Result<Option<CommandResult>, CommandError> {
+        let Some(deleted) = project.scenes.iter().find(|scene| scene.id == self.scene_id)
+        else {
+            return Ok(None);
+        };
+        if deleted.is_main {
+            return Ok(None);
+        }
+
+        self.saved_scenes = Some(project.scenes.clone());
+        self.saved_current_scene_id = Some(project.current_scene_id.clone());
+
+        project.scenes.retain(|scene| scene.id != self.scene_id);
+
+        if project.current_scene_id == self.scene_id {
+            let fallback_id = project
+                .scenes
+                .iter()
+                .find(|scene| scene.is_main)
+                .map(|scene| scene.id.clone());
+            if let Some(fallback_id) = fallback_id {
+                project.current_scene_id = fallback_id;
+            }
+        }
+        Ok(None)
+    }
+
+    fn undo(&mut self, project: &mut Project) {
+        let (Some(saved_scenes), Some(saved_current_scene_id)) =
+            (&self.saved_scenes, &self.saved_current_scene_id)
+        else {
+            return;
+        };
+        project.scenes = saved_scenes.clone();
+        project.current_scene_id = saved_current_scene_id.clone();
+    }
+}
diff --git a/rust/crates/commands/src/scene/mod.rs b/rust/crates/commands/src/scene/mod.rs
new file mode 100644
index 00000000..10d687c1
--- /dev/null
+++ b/rust/crates/commands/src/scene/mod.rs
@@ -0,0 +1,15 @@
+pub mod create_scene;
+pub mod delete_scene;
+pub mod move_bookmark;
+pub mod remove_bookmark;
+pub mod rename_scene;
+pub mod toggle_bookmark;
+pub mod update_bookmark;
+
+pub use create_scene::CreateSceneCommand;
+pub use delete_scene::DeleteSceneCommand;
+pub use move_bookmark::MoveBookmarkCommand;
+pub use remove_bookmark::RemoveBookmarkCommand;
+pub use rename_scene::RenameSceneCommand;
+pub use toggle_bookmark::ToggleBookmarkCommand;
+pub use update_bookmark::UpdateBookmarkCommand;
diff --git a/rust/crates/commands/src/scene/move_bookmark.rs b/rust/crates/commands/src/scene/move_bookmark.rs
new file mode 100644
index 00000000..dddef11f
--- /dev/null
+++ b/rust/crates/commands/src/scene/move_bookmark.rs
@@ -0,0 +1,50 @@
+use scene::Project;
+use time::MediaTime;
+
+use crate::bookmarks::{get_frame_time, move_bookmark_in_array};
+use crate::command::{Command, CommandError, CommandResult};
+use crate::project_ext::active_scene_mut;
+
+pub struct MoveBookmarkCommand {
+    from_time: MediaTime,
+    to_time: MediaTime,
+    saved_bookmarks: Option<Vec<scene::Bookmark>>,
+}
+
+impl MoveBookmarkCommand {
+    pub fn new(from_time: MediaTime, to_time: MediaTime) -> Self {
+        Self {
+            from_time,
+            to_time,
+            saved_bookmarks: None,
+        }
+    }
+}
+
+impl Command for MoveBookmarkCommand {
+    fn execute(
+        &mut self,
+        project: &mut Project,
+    ) -> Result<Option<CommandResult>, CommandError> {
+        let fps = project.settings.fps;
+        let Some(scene) = active_scene_mut(project) else {
+            return Ok(None);
+        };
+
+        self.saved_bookmarks = Some(scene.bookmarks.clone());
+        let from_frame_time = get_frame_time(self.from_time, fps);
+        let to_frame_time = get_frame_time(self.to_time, fps);
+        scene.bookmarks =
+            move_bookmark_in_array(&scene.bookmarks, from_frame_time, to_frame_time);
+        Ok(None)
+    }
+
+    fn undo(&mut self, project: &mut Project) {
+        let Some(saved) = &self.saved_bookmarks else {
+            return;
+        };
+        if let Some(scene) = active_scene_mut(project) {
+            scene.bookmarks = saved.clone();
+        }
+    }
+}
diff --git a/rust/crates/commands/src/scene/remove_bookmark.rs b/rust/crates/commands/src/scene/remove_bookmark.rs
new file mode 100644
index 00000000..f8fe0c5a
--- /dev/null
+++ b/rust/crates/commands/src/scene/remove_bookmark.rs
@@ -0,0 +1,54 @@
+use scene::Project;
+use time::MediaTime;
+
+use crate::bookmarks::{get_frame_time, remove_bookmark_from_array};
+use crate::command::{Command, CommandError, CommandResult};
+use crate::project_ext::active_scene_mut;
+
+pub struct RemoveBookmarkCommand {
+    time: MediaTime,
+    frame_time: MediaTime,
+    saved_bookmarks: Option<Vec<scene::Bookmark>>,
+}
+
+impl RemoveBookmarkCommand {
+    pub fn new(time: MediaTime) -> Self {
+        Self {
+            time,
+            frame_time: MediaTime::ZERO,
+            saved_bookmarks: None,
+        }
+    }
+}
+
+impl Command for RemoveBookmarkCommand {
+    fn execute(
+        &mut self,
+        project: &mut Project,
+    ) -> Result<Option<CommandResult>, CommandError> {
+        let fps = project.settings.fps;
+        let Some(scene) = active_scene_mut(project) else {
+            return Ok(None);
+        };
+
+        self.saved_bookmarks = Some(scene.bookmarks.clone());
+        self.frame_time = get_frame_time(self.time, fps);
+
+        let updated = remove_bookmark_from_array(&scene.bookmarks, self.frame_time);
+        if updated.len() == scene.bookmarks.len() {
+            return Ok(None);
+        }
+
+        scene.bookmarks = updated;
+        Ok(None)
+    }
+
+    fn undo(&mut self, project: &mut Project) {
+        let Some(saved) = &self.saved_bookmarks else {
+            return;
+        };
+        if let Some(scene) = active_scene_mut(project) {
+            scene.bookmarks = saved.clone();
+        }
+    }
+}
diff --git a/rust/crates/commands/src/scene/rename_scene.rs b/rust/crates/commands/src/scene/rename_scene.rs
new file mode 100644
index 00000000..4876fb9b
--- /dev/null
+++ b/rust/crates/commands/src/scene/rename_scene.rs
@@ -0,0 +1,58 @@
+use scene::Project;
+
+use crate::command::{Command, CommandError, CommandResult};
+
+pub struct RenameSceneCommand {
+    scene_id: String,
+    new_name: String,
+    saved_name: Option<String>,
+    saved_updated_at: Option<chrono::DateTime<chrono::Utc>>,
+}
+
+impl RenameSceneCommand {
+    pub fn new(scene_id: impl Into<String>, new_name: impl Into<String>) -> Self {
+        Self {
+            scene_id: scene_id.into(),
+            new_name: new_name.into(),
+            saved_name: None,
+            saved_updated_at: None,
+        }
+    }
+}
+
+impl Command for RenameSceneCommand {
+    fn execute(
+        &mut self,
+        project: &mut Project,
+    ) -> Result<Option<CommandResult>, CommandError> {
+        let Some(scene) = project
+            .scenes
+            .iter_mut()
+            .find(|scene| scene.id == self.scene_id)
+        else {
+            return Ok(None);
+        };
+
+        self.saved_name = Some(scene.name.clone());
+        self.saved_updated_at = Some(scene.updated_at);
+        scene.name = self.new_name.clone();
+        scene.updated_at = chrono::Utc::now();
+        Ok(None)
+    }
+
+    fn undo(&mut self, project: &mut Project) {
+        let (Some(saved_name), Some(saved_updated_at)) =
+            (&self.saved_name, self.saved_updated_at)
+        else {
+            return;
+        };
+        if let Some(scene) = project
+            .scenes
+            .iter_mut()
+            .find(|scene| scene.id == self.scene_id)
+        {
+            scene.name = saved_name.clone();
+            scene.updated_at = saved_updated_at;
+        }
+    }
+}
diff --git a/rust/crates/commands/src/scene/toggle_bookmark.rs b/rust/crates/commands/src/scene/toggle_bookmark.rs
new file mode 100644
index 00000000..054e1c78
--- /dev/null
+++ b/rust/crates/commands/src/scene/toggle_bookmark.rs
@@ -0,0 +1,48 @@
+use scene::Project;
+
+use crate::bookmarks::{get_frame_time, toggle_bookmark_in_array};
+use crate::command::{Command, CommandError, CommandResult};
+use crate::project_ext::active_scene_mut;
+use time::MediaTime;
+
+pub struct ToggleBookmarkCommand {
+    time: MediaTime,
+    frame_time: MediaTime,
+    saved_bookmarks: Option<Vec<scene::Bookmark>>,
+}
+
+impl ToggleBookmarkCommand {
+    pub fn new(time: MediaTime) -> Self {
+        Self {
+            time,
+            frame_time: MediaTime::ZERO,
+            saved_bookmarks: None,
+        }
+    }
+}
+
+impl Command for ToggleBookmarkCommand {
+    fn execute(
+        &mut self,
+        project: &mut Project,
+    ) -> Result<Option<CommandResult>, CommandError> {
+        let fps = project.settings.fps;
+        let Some(scene) = active_scene_mut(project) else {
+            return Ok(None);
+        };
+
+        self.saved_bookmarks = Some(scene.bookmarks.clone());
+        self.frame_time = get_frame_time(self.time, fps);
+        scene.bookmarks = toggle_bookmark_in_array(&scene.bookmarks, self.frame_time);
+        Ok(None)
+    }
+
+    fn undo(&mut self, project: &mut Project) {
+        let Some(saved) = &self.saved_bookmarks else {
+            return;
+        };
+        if let Some(scene) = active_scene_mut(project) {
+            scene.bookmarks = saved.clone();
+        }
+    }
+}
diff --git a/rust/crates/commands/src/scene/update_bookmark.rs b/rust/crates/commands/src/scene/update_bookmark.rs
new file mode 100644
index 00000000..f2c9b94e
--- /dev/null
+++ b/rust/crates/commands/src/scene/update_bookmark.rs
@@ -0,0 +1,49 @@
+use scene::Project;
+use time::MediaTime;
+
+use crate::bookmarks::{BookmarkPatch, get_frame_time, update_bookmark_in_array};
+use crate::command::{Command, CommandError, CommandResult};
+use crate::project_ext::active_scene_mut;
+
+pub struct UpdateBookmarkCommand {
+    time: MediaTime,
+    updates: BookmarkPatch,
+    saved_bookmarks: Option<Vec<scene::Bookmark>>,
+}
+
+impl UpdateBookmarkCommand {
+    pub fn new(time: MediaTime, updates: BookmarkPatch) -> Self {
+        Self {
+            time,
+            updates,
+            saved_bookmarks: None,
+        }
+    }
+}
+
+impl Command for UpdateBookmarkCommand {
+    fn execute(
+        &mut self,
+        project: &mut Project,
+    ) -> Result<Option<CommandResult>, CommandError> {
+        let fps = project.settings.fps;
+        let Some(scene) = active_scene_mut(project) else {
+            return Ok(None);
+        };
+
+        self.saved_bookmarks = Some(scene.bookmarks.clone());
+        let frame_time = get_frame_time(self.time, fps);
+        scene.bookmarks =
+            update_bookmark_in_array(&scene.bookmarks, frame_time, &self.updates);
+        Ok(None)
+    }
+
+    fn undo(&mut self, project: &mut Project) {
+        let Some(saved) = &self.saved_bookmarks else {
+            return;
+        };
+        if let Some(scene) = active_scene_mut(project) {
+            scene.bookmarks = saved.clone();
+        }
+    }
+}