Allow login to SaaS for desktop instead of offline mode (#4941)

# Description of Changes
Makes the desktop options to sign in with your Stirling account, or sign
into self-hosted:

<img width="608" height="456" alt="image"
src="https://github.com/user-attachments/assets/a49988ab-db3f-4333-b242-790aee5c07c6"
/>

The first option still runs everything locally, just enforces that
you've signed in for now. Future work will enable sending operations
that can't be run locally to the server.

frontend/src-tauri/src/commands/connection.rs

@@ -31,7 +31,7 @@ pub async fn get_connection_config(
     let mode = store
         .get(CONNECTION_MODE_KEY)
         .and_then(|v| serde_json::from_value(v.clone()).ok())
-        .unwrap_or(ConnectionMode::Offline);
+        .unwrap_or(ConnectionMode::SaaS);
 
     let server_config: Option<ServerConfig> = store
         .get(SERVER_CONFIG_KEY)
@@ -109,3 +109,22 @@ pub async fn is_first_launch(app_handle: AppHandle) -> Result<bool, String> {
 
     Ok(!setup_completed)
 }
+
+#[tauri::command]
+pub async fn reset_setup_completion(app_handle: AppHandle) -> Result<(), String> {
+    log::info!("Resetting setup completion flag");
+
+    let store = app_handle
+        .store(STORE_FILE)
+        .map_err(|e| format!("Failed to access store: {}", e))?;
+
+    // Reset setup completion flag to force SetupWizard on next launch
+    store.set(FIRST_LAUNCH_KEY, serde_json::json!(false));
+
+    store
+        .save()
+        .map_err(|e| format!("Failed to save store: {}", e))?;
+
+    log::info!("Setup completion flag reset successfully");
+    Ok(())
+}