Feat: UI/UX and ducking compressor

tests/forth/temporal.rs

@@ -338,3 +338,59 @@ fn arp_mixed_cycle_and_arp() {
     assert!(approx_eq(notes[4], 67.0));
     assert!(approx_eq(notes[5], 67.0));
 }
+
+// --- every+ / except+ tests ---
+
+#[test]
+fn every_offset_fires_at_offset() {
+    for iter in 0..8 {
+        let ctx = ctx_with(|c| c.iter = iter);
+        let f = forth();
+        let outputs = f.evaluate(r#""kick" s { . } 4 2 every+"#, &ctx).unwrap();
+        if iter % 4 == 2 {
+            assert_eq!(outputs.len(), 1, "iter={}: should fire", iter);
+        } else {
+            assert_eq!(outputs.len(), 0, "iter={}: should not fire", iter);
+        }
+    }
+}
+
+#[test]
+fn every_offset_wraps_large_offset() {
+    // offset 6 with n=4 → 6 % 4 = 2, same as offset 2
+    for iter in 0..8 {
+        let ctx = ctx_with(|c| c.iter = iter);
+        let f = forth();
+        let outputs = f.evaluate(r#""kick" s { . } 4 6 every+"#, &ctx).unwrap();
+        if iter % 4 == 2 {
+            assert_eq!(outputs.len(), 1, "iter={}: should fire (wrapped offset)", iter);
+        } else {
+            assert_eq!(outputs.len(), 0, "iter={}: should not fire", iter);
+        }
+    }
+}
+
+#[test]
+fn except_offset_inverse() {
+    for iter in 0..8 {
+        let ctx = ctx_with(|c| c.iter = iter);
+        let f = forth();
+        let outputs = f.evaluate(r#""kick" s { . } 4 2 except+"#, &ctx).unwrap();
+        if iter % 4 != 2 {
+            assert_eq!(outputs.len(), 1, "iter={}: should fire", iter);
+        } else {
+            assert_eq!(outputs.len(), 0, "iter={}: should not fire", iter);
+        }
+    }
+}
+
+#[test]
+fn every_offset_zero_is_same_as_every() {
+    for iter in 0..8 {
+        let ctx = ctx_with(|c| c.iter = iter);
+        let f = forth();
+        let a = f.evaluate(r#""kick" s { . } 3 every"#, &ctx).unwrap();
+        let b = f.evaluate(r#""kick" s { . } 3 0 every+"#, &ctx).unwrap();
+        assert_eq!(a.len(), b.len(), "iter={}: every and every+ 0 should match", iter);
+    }
+}