Video ads (watch-to-earn): duration-tiered pricing, escape-proof player, per-view charge

- New 'video' campaign type; MP4/WebM upload or direct https link + required-watch tier (10/30/60s → 3/7/12 cr per view; viewer earns 1/2/4)
- Composer: video fields, tier dropdown, live price hint
- Earn credits > Watch videos sub-tab: no-seek player, server-clock watch floor, daily cap, self-exclusion, single-use tokens
- media-src CSP for direct-link/hosted video; video skips frame-check

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

public/view.html

@@ -4,7 +4,7 @@
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width,initial-scale=1">
 <title>Viewing ad — InstantAdPay</title>
-<link rel="stylesheet" href="/assets/site.css?v=20260905w">
+<link rel="stylesheet" href="/assets/site.css?v=20260905x">
 <style>
   html,body{height:100%;margin:0;overflow:hidden}
   .vw{display:flex;flex-direction:column;height:100vh;height:100dvh;background:var(--bg,#04110c);color:var(--ink,#e8fff7)}
@@ -43,6 +43,6 @@
   </div>
   <iframe class="vframe" id="vFrame" sandbox="allow-scripts allow-same-origin allow-forms allow-popups" referrerpolicy="no-referrer" title="Advertiser site"></iframe>
 </div>
-<script src="/assets/view.js?v=20260905w"></script>
+<script src="/assets/view.js?v=20260905x"></script>
 </body>
 </html>