sidebar: Make project reordering key-bindable (#62695)

# Objective

- The sidebar already supports moving project groups through its **Move
Up** and **Move Down** context-menu entries, but those entries use
callbacks that cannot be referenced from `keymap.json`. Moving a project
several positions therefore requires reopening the menu for every step.
- Follow-up to #57448. Related to #61647.

## Solution

- Add `multi_workspace::MoveProjectUp` and
`multi_workspace::MoveProjectDown` actions. The handlers resolve the
active project group and delegate to the existing `MultiWorkspace`
reordering methods, keeping ordering and persistence behavior unchanged.
- Associate the actions with the existing context-menu entries so
configured shortcuts are shown alongside the menu commands. The menu
callbacks still operate on the project that was clicked.

## Testing

- Added a GPUI test that dispatches both actions and verifies that the
active project group moves in the expected direction and remains
unchanged at list boundaries:
- `cargo test -p workspace test_move_active_project_group_actions --
--nocapture`
- Manually verified on macOS with an isolated Zed user-data directory
and three project folders:
  - Assigned custom shortcuts to both actions in `keymap.json`.
  - Confirmed that the active project moves up and down in the sidebar.
- Ran formatting, compilation, and lint checks:
  - `cargo fmt --all -- --check`
  - `cargo check -p sidebar`
- `./script/clippy -p workspace -p sidebar -p gpui_platform --features
gpui_platform/runtime_shaders`

## Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content adheres to Zed's UI standards
([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
and
[icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md)
guidelines)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

## Showcase

<details>
  <summary>Move projects with custom keybindings</summary>


https://github.com/user-attachments/assets/09432817-318b-484e-b630-a6012e9599cd

</details>

---

Release Notes:

- Sidebar: Added key-bindable actions for moving projects up and down.

crates/sidebar/src/sidebar.rs

@@ -63,10 +63,10 @@ use unicode_segmentation::UnicodeSegmentation as _;
 use util::ResultExt as _;
 use util::path_list::PathList;
 use workspace::{
-    CloseWindow, FocusWorkspaceSidebar, MultiWorkspace, MultiWorkspaceEvent, NextProject,
-    NextThread, Open, OpenMode, PreviousProject, PreviousThread, ProjectGroupKey, RemovalIntent,
-    SaveIntent, Sidebar as WorkspaceSidebar, SidebarSide, Toast, ToggleWorkspaceSidebar, Workspace,
-    notifications::NotificationId, sidebar_side_context_menu,
+    CloseWindow, FocusWorkspaceSidebar, MoveProjectDown, MoveProjectUp, MultiWorkspace,
+    MultiWorkspaceEvent, NextProject, NextThread, Open, OpenMode, PreviousProject, PreviousThread,
+    ProjectGroupKey, RemovalIntent, SaveIntent, Sidebar as WorkspaceSidebar, SidebarSide, Toast,
+    ToggleWorkspaceSidebar, Workspace, notifications::NotificationId, sidebar_side_context_menu,
 };
 
 use git_ui_core::worktree_service::{RemoteBranchName, worktree_create_targets};
@@ -3073,6 +3073,7 @@ impl Sidebar {
                             this.separator()
                                 .item(
                                     ContextMenuEntry::new("Move Up")
+                                        .action(Box::new(MoveProjectUp))
                                         .disabled(!can_move_up)
                                         .handler(move |_window, cx| {
                                             move_up_multi_workspace
@@ -3087,6 +3088,7 @@ impl Sidebar {
                                 )
                                 .item(
                                     ContextMenuEntry::new("Move Down")
+                                        .action(Box::new(MoveProjectDown))
                                         .disabled(!can_move_down)
                                         .handler(move |_window, cx| {
                                             move_down_multi_workspace

crates/workspace/src/multi_workspace.rs

@@ -46,6 +46,10 @@ actions!(
         NextProject,
         /// Activates the previous project in the sidebar.
         PreviousProject,
+        /// Moves the active project up in the sidebar.
+        MoveProjectUp,
+        /// Moves the active project down in the sidebar.
+        MoveProjectDown,
         /// Activates the next thread in sidebar order.
         NextThread,
         /// Activates the previous thread in sidebar order.
@@ -2109,6 +2113,18 @@ impl Render for MultiWorkspace {
                             }
                         }),
                     )
+                    .on_action(
+                        cx.listener(|this: &mut Self, _: &MoveProjectUp, _window, cx| {
+                            let key = this.project_group_key_for_workspace(this.workspace(), cx);
+                            this.move_project_group_up(&key, cx);
+                        }),
+                    )
+                    .on_action(
+                        cx.listener(|this: &mut Self, _: &MoveProjectDown, _window, cx| {
+                            let key = this.project_group_key_for_workspace(this.workspace(), cx);
+                            this.move_project_group_down(&key, cx);
+                        }),
+                    )
                     .on_action(cx.listener(|this: &mut Self, _: &NextThread, window, cx| {
                         if let Some(sidebar) = &this.sidebar {
                             sidebar.cycle_thread(true, window, cx);

crates/workspace/src/multi_workspace_tests.rs

@@ -221,6 +221,56 @@ async fn test_project_group_keys_add_workspace(cx: &mut TestAppContext) {
     });
 }
 
+#[gpui::test]
+async fn test_move_active_project_group_actions(cx: &mut TestAppContext) {
+    init_test(cx);
+    let fs = FakeFs::new(cx.executor());
+    fs.insert_tree("/root_a", json!({ "file.txt": "" })).await;
+    fs.insert_tree("/root_b", json!({ "file.txt": "" })).await;
+    let project_a = Project::test(fs.clone(), ["/root_a".as_ref()], cx).await;
+    let project_b = Project::test(fs, ["/root_b".as_ref()], cx).await;
+
+    let key_a = project_a.read_with(cx, |project, cx| project.project_group_key(cx));
+    let key_b = project_b.read_with(cx, |project, cx| project.project_group_key(cx));
+
+    let (multi_workspace, cx) =
+        cx.add_window_view(|window, cx| MultiWorkspace::test_new(project_a, window, cx));
+    multi_workspace.update_in(cx, |multi_workspace, window, cx| {
+        multi_workspace.test_add_workspace(project_b, window, cx);
+    });
+
+    assert_eq!(
+        multi_workspace.read_with(cx, |multi_workspace, _| {
+            multi_workspace.project_group_keys()
+        }),
+        vec![key_b.clone(), key_a.clone()]
+    );
+
+    cx.dispatch_action(MoveProjectDown);
+    assert_eq!(
+        multi_workspace.read_with(cx, |multi_workspace, _| {
+            multi_workspace.project_group_keys()
+        }),
+        vec![key_a.clone(), key_b.clone()]
+    );
+
+    cx.dispatch_action(MoveProjectDown);
+    assert_eq!(
+        multi_workspace.read_with(cx, |multi_workspace, _| {
+            multi_workspace.project_group_keys()
+        }),
+        vec![key_a.clone(), key_b.clone()]
+    );
+
+    cx.dispatch_action(MoveProjectUp);
+    assert_eq!(
+        multi_workspace.read_with(cx, |multi_workspace, _| {
+            multi_workspace.project_group_keys()
+        }),
+        vec![key_b, key_a]
+    );
+}
+
 #[gpui::test]
 async fn test_open_new_window_does_not_open_sidebar_on_existing_window(cx: &mut TestAppContext) {
     init_test(cx);

crates/workspace/src/workspace.rs

@@ -31,11 +31,11 @@ mod workspace_settings;
 
 pub use dock::Panel;
 pub use multi_workspace::{
-    CloseWorkspaceSidebar, DraggedSidebar, FocusWorkspaceSidebar, MoveProjectToNewWindow,
-    MultiWorkspace, MultiWorkspaceEvent, NewThread, NextProject, NextThread, PreviousProject,
-    PreviousThread, ProjectGroup, ProjectGroupKey, RemovalIntent, SerializedProjectGroupState,
-    Sidebar, SidebarEvent, SidebarHandle, SidebarRenderState, SidebarSide, ToggleWorkspaceSidebar,
-    sidebar_side_context_menu,
+    CloseWorkspaceSidebar, DraggedSidebar, FocusWorkspaceSidebar, MoveProjectDown,
+    MoveProjectToNewWindow, MoveProjectUp, MultiWorkspace, MultiWorkspaceEvent, NewThread,
+    NextProject, NextThread, PreviousProject, PreviousThread, ProjectGroup, ProjectGroupKey,
+    RemovalIntent, SerializedProjectGroupState, Sidebar, SidebarEvent, SidebarHandle,
+    SidebarRenderState, SidebarSide, ToggleWorkspaceSidebar, sidebar_side_context_menu,
 };
 pub use path_list::{PathList, SerializedPathList};
 pub use remote::{