test: verify review highlight controls (#6)

validation/issue-6-result.json

@@ -0,0 +1,21 @@
+{
+  "status": "passed",
+  "target_conduits": 207,
+  "red_pixels_on": 4457,
+  "red_pixels_off": 0,
+  "original_colors_restored": true,
+  "checks": [
+    "target IDs",
+    "red pixels",
+    "1 second phases",
+    "exact original pixel restoration",
+    "timer cancellation",
+    "steady mode",
+    "layer visibility",
+    "selection reasons",
+    "3 unplaced facilities",
+    "reset",
+    "reduced motion",
+    "no page errors"
+  ]
+}