harden remote daemon recovery and log draining

src-tauri/src/commands/remote_backend.rs

@@ -9,7 +9,7 @@ use tauri::{AppHandle, State};
 
 use crate::services::remote_backend::{
     self, daemon::RemoteDirListing, daemon::RemoteToolProbe, RemoteBackendConnection,
-    RemoteBackendError, RemoteBackendRegistry, RemoteBackendStatus,
+    RemoteBackendError, RemoteBackendErrorKind, RemoteBackendRegistry, RemoteBackendStatus,
 };
 
 #[tauri::command]
@@ -41,8 +41,30 @@ pub async fn remote_backend_disconnect(
     host: String,
     expected_generation: Option<u64>,
 ) -> Result<(), RemoteBackendError> {
-    remote_backend::disconnect_generation(&app, &registry, &host, expected_generation);
-    Ok(())
+    if remote_backend::disconnect_generation(&app, &registry, &host, expected_generation) {
+        Ok(())
+    } else if expected_generation.is_some() {
+        Err(RemoteBackendError::new(
+            RemoteBackendErrorKind::DaemonChanged,
+            "Remote backend changed before disconnect completed",
+        ))
+    } else {
+        Ok(())
+    }
+}
+
+#[tauri::command]
+pub async fn remote_backend_forget(
+    registry: State<'_, RemoteBackendRegistry>,
+    host: String,
+) -> Result<(), RemoteBackendError> {
+    if registry.forget(&host).await {
+        Ok(())
+    } else {
+        Err(RemoteBackendError::internal(
+            "Cannot forget an active remote backend",
+        ))
+    }
 }
 
 #[tauri::command]
@@ -51,8 +73,16 @@ pub async fn remote_backend_shutdown(
     registry: State<'_, RemoteBackendRegistry>,
     host: String,
     expected_instance_token: Option<String>,
+    expected_generation: Option<u64>,
 ) -> Result<(), RemoteBackendError> {
-    remote_backend::shutdown(&app, &registry, &host, expected_instance_token.as_deref()).await
+    remote_backend::shutdown(
+        &app,
+        &registry,
+        &host,
+        expected_instance_token.as_deref(),
+        expected_generation,
+    )
+    .await
 }
 
 #[tauri::command]

src-tauri/src/lib.rs

@@ -553,6 +553,7 @@ pub fn run() {
             commands::remote_backend::list_ssh_config_hosts,
             commands::remote_backend::remote_backend_connect,
             commands::remote_backend::remote_backend_disconnect,
+            commands::remote_backend::remote_backend_forget,
             commands::remote_backend::remote_backend_shutdown,
             commands::remote_backend::list_remote_backends,
             commands::remote_backend::check_remote_host,