Fix iframe recursion and remove all localStorage/cookies site-wide

- Add target="_top" to all ← SPACE / back-to-root links so navigating
  back to index.html breaks out of the content iframe instead of loading
  it recursively inside itself (Images, Music, Watchlists hubs)
- Remove all localStorage usage: visited-star tracking in index.html
  (resets each visit, no persistence without storage), and lightbox
  "show once" guards in all section pages (lightboxes now show on every
  load — Videos, Watchlists, Music). build.py templates updated so
  future generated pages stay clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Videos/cringe-pit.html

@@ -342,13 +342,10 @@
         function closeGate() {
             const gate = document.getElementById('welcome-gate');
             gate.classList.remove('active');
-            localStorage.setItem('cringe_pit_visited', 'true');
         }
 
         document.addEventListener('DOMContentLoaded', () => {
-            if (!localStorage.getItem('cringe_pit_visited')) {
-                document.getElementById('welcome-gate').classList.add('active');
-            }
+            document.getElementById('welcome-gate').classList.add('active');
         });
     </script>
 </body>

Videos/nomad-soul.html

@@ -403,13 +403,10 @@
         function closeGate() {
             const gate = document.getElementById('welcome-gate');
             gate.classList.remove('active');
-            localStorage.setItem('nomad_visited', 'true');
         }
 
         document.addEventListener('DOMContentLoaded', () => {
-            if (!localStorage.getItem('nomad_visited')) {
-                document.getElementById('welcome-gate').classList.add('active');
-            }
+            document.getElementById('welcome-gate').classList.add('active');
         });
     </script>
 </body>

Videos/renegade-storyteller.html

@@ -397,13 +397,10 @@
         function closeGate() {
             const gate = document.getElementById('welcome-gate');
             gate.classList.remove('active');
-            localStorage.setItem('renegade_visited', 'true');
         }
 
         document.addEventListener('DOMContentLoaded', () => {
-            if (!localStorage.getItem('renegade_visited')) {
-                document.getElementById('welcome-gate').classList.add('active');
-            }
+            document.getElementById('welcome-gate').classList.add('active');
         });
     </script>
 </body>