feat: Restructure TXT verification into a separate _vercel.himanshupal subdomain JSON file

domains/_vercel.himanshupal.json

@@ -0,0 +1,11 @@
+{
+  "owner": {
+    "username": "himanshu-pal419845",
+    "email": "himanshupal19845@gmail.com"
+  },
+  "records": {
+    "TXT": [
+      "vc-domain-verify=himanshupal.is-a.dev,b611613f7a61c169f609"
+    ]
+  }
+}

domains/himanshupal.json

@@ -4,9 +4,6 @@
     "email": "himanshupal19845@gmail.com"
   },
   "records": {
-    "CNAME": "himanshupal-portfolio-2026.vercel.app",
-    "TXT": {
-      "_vercel": "vc-domain-verify=himanshupal.is-a.dev,b611613f7a61c169f609"
-    }
+    "CNAME": "himanshupal-portfolio-2026.vercel.app"
   }
 }