Add: XSS Defender quest

data/quests.json

@@ -995,6 +995,31 @@
       ],
       "difficulty": "Hard",
       "status": "live"
+    },
+    {
+      "id": "xss-defender",
+      "name": "XSS Defender",
+      "shortDescription": "Interactive web security quest game teaching Cross-Site Scripting (XSS) prevention, HTML sanitization, and Content Security Policy (CSP) headers.",
+      "longDescription": "## XSS Defender\n\nAn interactive web security quest game that teaches Cross-Site Scripting (XSS) prevention, HTML sanitizer policies (DOMPurify / HTML Sanitizer API), and Content Security Policy (CSP) directive configurations.\n\n### Features\n\n- Interactive XSS Attack Simulator: Live rendering of attack payloads in an isolated preview sandbox\n- Progressive Security Levels: Level-based scenarios covering Reflected XSS entity encoding, DOM sanitization policies, CSP headers, and event handler attribute injections\n- Real-Time Vulnerability Analyzer: Live feedback indicating whether script execution was blocked or succeeded\n- Web Audio Synthesizer SFX: Audio feedback for firewall alerts, sanitization shield activations, and level completion fanfares\n- Built-In Web Security Manual: Cheatsheet covering XSS prevention guidelines and CSP directive syntax",
+      "category": "js-fundamentals",
+      "tags": [
+        "csp",
+        "dompurify",
+        "game",
+        "quest",
+        "sanitizer",
+        "security",
+        "web-security",
+        "xss"
+      ],
+      "techStack": [
+        "CSS3",
+        "HTML5",
+        "Vanilla JS",
+        "Web Audio API"
+      ],
+      "difficulty": "Medium",
+      "status": "live"
     }
   ]
 }