Fix XDG_RUNTIME_DIR dependency by adding fallback to temp directory

common/src/paths.rs

@@ -6,9 +6,17 @@ use xdg::BaseDirectories;
 
 /// Get the path to the Cypraea socket.
 pub fn socket_path() -> Result<PathBuf> {
-    // Use XDG_RUNTIME_DIR if available, or fall back to a temporary directory
-    let xdg = BaseDirectories::new().context("Failed to initialize XDG base directories")?;
-    Ok(xdg.place_runtime_file("cypraea.sock")?)
+    // Try to use XDG_RUNTIME_DIR if available
+    if let Ok(xdg) = BaseDirectories::new() {
+        if let Ok(path) = xdg.place_runtime_file("cypraea.sock") {
+            return Ok(path);
+        }
+    }
+    
+    // Fallback to a temporary directory if XDG_RUNTIME_DIR is not set
+    let tmp_dir = std::env::temp_dir();
+    let socket_path = tmp_dir.join("cypraea.sock");
+    Ok(socket_path)
 }
 
 /// Get the path to the Cypraea database directory.