feat(core,fuse,gui,cli): restore to this computer per device

ListDeviceRestorableFolders and RestoreDeviceFolders read another
registered device's folders and attach them with that device's share,
without changing this machine's cached device. The Computers page moves
restore into each computer's menu, and pdfs sync restore takes --device.

crates/pdfs-core/src/control.rs

@@ -443,6 +443,18 @@ pub enum Request {
     /// Attach the given remote device folders to local paths and sync them down.
     /// Replies with [`Response::Ok`].
     RestoreSyncFolders { items: Vec<RestoreItem> },
+    /// [`Request::ListRestorableFolders`] for another registered device, by
+    /// uid, so its folders can be synced down to this machine. Replies with
+    /// [`Response::RestorableFolders`].
+    ListDeviceRestorableFolders { device: String },
+    /// [`Request::RestoreSyncFolders`] for folders under another device. A
+    /// separate variant rather than an optional field: an older daemon that
+    /// ignored the field would attach the folders under this machine's device
+    /// share instead. Replies with [`Response::Ok`].
+    RestoreDeviceFolders {
+        device: String,
+        items: Vec<RestoreItem>,
+    },
 
     // ---- sharing a node ---------------------------------------------------
     /// Invite `emails` (Proton and/or external addresses, auto-detected) to the
@@ -2491,6 +2503,17 @@ mod tests {
                     mode: "mirror".into(),
                 }],
             },
+            Request::ListDeviceRestorableFolders {
+                device: "dev-2".into(),
+            },
+            Request::RestoreDeviceFolders {
+                device: "dev-2".into(),
+                items: vec![RestoreItem {
+                    remote_uid: "vol~link".into(),
+                    local_path: "/home/me/Work".into(),
+                    mode: "ondemand".into(),
+                }],
+            },
             Request::ShareNode {
                 path: "a/b".into(),
                 emails: vec!["x@proton.me".into(), "y@example.com".into()],