feat(cli,fuse,core): copy files and folders on Proton Drive

`pdfs copy PATH... NEW_PARENT` sends a new control request, Copy, which
copies a file with its content or a folder with its subtree on Proton
Drive through proton-drive-rs's copy_node. Nothing is downloaded or
uploaded. A name already taken in the destination gets the next free
" (n)" suffix through get_available_name.

A copy cannot wait in the queue, because Drive copies what it holds.
So it is refused offline, and while the mount still owes Drive part of
the node: a local placeholder, a queued op, unsaved writes, or, for a
folder, any queued op at all. Local-first does not change this.

DriveApi gains copy_node and get_available_name, and the fake drive
copies subtrees, so a FUSE sim test covers the copy, the suffix, the
folder subtree and both refusals. The activity feed logs a new Copy
kind, translated in every catalog.

Needs the proton-drive-rs release that adds copy_node; until then, build
with a [patch.crates-io] pointing at proton-sdk-rs.

crates/pdfs-cli/src/main.rs

@@ -356,6 +356,18 @@ enum Command {
         #[arg(required = true, num_args = 2.., value_name = "PATH")]
         paths: Vec<PathBuf>,
     },
+    /// Copy files or folders into another folder in My files via the running
+    /// daemon.
+    ///
+    /// The copy happens on Proton Drive, so nothing is downloaded or uploaded,
+    /// unlike `cp` inside the mount. A name already taken in the destination
+    /// gets a " (1)" suffix. The last path is the destination folder.
+    Copy {
+        /// Files/folders to copy, then the destination folder: inside My files,
+        /// or relative to the mountpoint.
+        #[arg(required = true, num_args = 2.., value_name = "PATH")]
+        paths: Vec<PathBuf>,
+    },
     /// Trash a file or folder via the running daemon.
     Rm {
         /// File/folder path, inside My files or an on-demand synced folder, or
@@ -919,6 +931,10 @@ fn main() -> Result<()> {
             let new_parent = paths.pop().expect("clap requires at least two paths");
             cmd_move(paths, new_parent)
         }
+        Command::Copy { mut paths } => {
+            let new_parent = paths.pop().expect("clap requires at least two paths");
+            cmd_copy(paths, new_parent)
+        }
         Command::Rm { path } => cmd_rm(path),
         Command::Mkdir { parent, name } => cmd_mkdir(parent, name),
         Command::Upload { sources, parent } => cmd_upload(sources, parent),
@@ -1765,6 +1781,7 @@ fn activity_verb(kind: pdfs_core::control::ActivityKind) -> &'static str {
         Sync => "sync",
         Rename => "rename",
         Move => "move",
+        Copy => "copy",
         CreateFolder => "mkdir",
         Trash => "trash",
         Restore => "restore",
@@ -2920,6 +2937,35 @@ fn cmd_move(sources: Vec<PathBuf>, new_parent: PathBuf) -> Result<()> {
     Ok(())
 }
 
+fn cmd_copy(sources: Vec<PathBuf>, new_parent: PathBuf) -> Result<()> {
+    let new_parent = path_arg(&new_parent)?;
+    let mut failed = 0;
+    for source in &sources {
+        let outcome = path_arg(source).and_then(|path| {
+            match control_request(CtlRequest::Copy {
+                path,
+                new_parent: new_parent.clone(),
+            })? {
+                CtlResponse::Ok { message } => Ok(message),
+                CtlResponse::Error { message, kind } => bail!("{}", cli_error(kind, &message)),
+                other => bail!("unexpected response: {other:?}"),
+            }
+        });
+        match outcome {
+            Ok(message) => println!("{message}"),
+            Err(e) if sources.len() == 1 => return Err(e),
+            Err(e) => {
+                eprintln!("{}: {e:#}", source.display());
+                failed += 1;
+            }
+        }
+    }
+    if failed > 0 {
+        bail!("{failed} of {} could not be copied", sources.len());
+    }
+    Ok(())
+}
+
 fn cmd_rm(path: PathBuf) -> Result<()> {
     match control_request(CtlRequest::Delete {
         path: path_arg(&path)?,