SSH remote ui (#15129)

Still TODO:
* [x] hide this UI unless you have some ssh projects in settings
* [x] add the "open folder" flow with the new open picker
* [ ] integrate with recent projects / workspace restoration

Release Notes:

- N/A

crates/remote_server/Cargo.toml

@@ -33,6 +33,7 @@ rpc.workspace = true
 settings.workspace = true
 serde.workspace = true
 serde_json.workspace = true
+shellexpand.workspace = true
 smol.workspace = true
 util.workspace = true
 worktree.workspace = true

crates/remote_server/src/headless_project.rs

@@ -12,6 +12,7 @@ use rpc::{
     TypedEnvelope,
 };
 use settings::{Settings as _, SettingsStore};
+use smol::stream::StreamExt;
 use std::{
     path::{Path, PathBuf},
     sync::{atomic::AtomicUsize, Arc},
@@ -45,6 +46,7 @@ impl HeadlessProject {
         cx.subscribe(&buffer_store, Self::on_buffer_store_event)
             .detach();
 
+        session.add_request_handler(this.clone(), Self::handle_list_remote_directory);
         session.add_request_handler(this.clone(), Self::handle_add_worktree);
         session.add_request_handler(this.clone(), Self::handle_open_buffer_by_path);
 
@@ -87,10 +89,11 @@ impl HeadlessProject {
         message: TypedEnvelope<proto::AddWorktree>,
         mut cx: AsyncAppContext,
     ) -> Result<proto::AddWorktreeResponse> {
+        let path = shellexpand::tilde(&message.payload.path).to_string();
         let worktree = this
             .update(&mut cx.clone(), |this, _| {
                 Worktree::local(
-                    Path::new(&message.payload.path),
+                    Path::new(&path),
                     true,
                     this.fs.clone(),
                     this.next_entry_id.clone(),
@@ -157,6 +160,24 @@ impl HeadlessProject {
         })
     }
 
+    pub async fn handle_list_remote_directory(
+        this: Model<Self>,
+        envelope: TypedEnvelope<proto::ListRemoteDirectory>,
+        cx: AsyncAppContext,
+    ) -> Result<proto::ListRemoteDirectoryResponse> {
+        let expanded = shellexpand::tilde(&envelope.payload.path).to_string();
+        let fs = cx.read_model(&this, |this, _| this.fs.clone())?;
+
+        let mut entries = Vec::new();
+        let mut response = fs.read_dir(Path::new(&expanded)).await?;
+        while let Some(path) = response.next().await {
+            if let Some(file_name) = path?.file_name() {
+                entries.push(file_name.to_string_lossy().to_string());
+            }
+        }
+        Ok(proto::ListRemoteDirectoryResponse { entries })
+    }
+
     pub fn on_buffer_store_event(
         &mut self,
         _: Model<BufferStore>,