feat: add exit button for exam mode with URL parameter handling

css/main.css

@@ -1347,4 +1347,17 @@ h2:has(+ #exam-list:empty),  h2:has(+ #packet-list:empty){
     display: flex;
     align-items: center;
     gap: 15px;
+}
+
+.exit-exam-mode {
+    position: fixed;
+    bottom: 20px;
+    right: 20px;
+    background-color: #b71c1c;
+    color: white;
+    border: none;
+    padding: 10px 15px;
+    border-radius: 5px;
+    cursor: pointer;
+    z-index: 10000;
 }

js/main.js

@@ -66,6 +66,20 @@ let url_exam_mode = false;
     if (examParam !== null) {
       if (examParam === "1" || String(examParam).toLowerCase() === "true") {
         url_exam_mode = true;
+        let el = $("#load-exam-packet-instructions")
+        el.html("You are in exam mode.");
+        
+        let button = $("<button class='exit-exam-mode'>Exit Exam Mode</button>");
+
+        button.click(() => { 
+            // Remove exam_mode param from URL and reload page
+            params.delete("exam_mode");
+            const newUrl = `${window.location.pathname}?${params.toString()}`;
+            window.location.href = newUrl;
+        })
+        el.append(button);
+        el.append("<br/>Click on exam below to load it.");
+        
         log.debug("URL parameter enabled exam mode");
       }
     }