fix: popups occasionally getting jumbled with multiple bars

src/unique_id.rs

@@ -0,0 +1,9 @@
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+static COUNTER: AtomicUsize = AtomicUsize::new(1);
+
+/// Gets a `usize` ID value that is unique to the entire Ironbar instance.
+/// This is just an `AtomicUsize` that increments every time this function is called.
+pub fn get_unique_usize() -> usize {
+    COUNTER.fetch_add(1, Ordering::Relaxed)
+}