feat: demo GIF + MP4 in README

README.md

@@ -24,29 +24,15 @@
 ## See it in action
 
 <p align="center">
-  <img src="./assets/demo.gif" alt="Deploy Gate blocking a PR and requiring human approval" width="700">
-</p>
-
-
-PR opened → ❌ Blocked → Click approval → Human signs → ✅ Merge allowed
-
-
-Open a PR → Deploy Gate blocks it → click the approval link → approve & sign → return to GitHub → merge unlocked.
-
----
-
-## See it in action
-
-<p align="center">
-  <img src="./assets/demo-blocked-pr.png" alt="Deploy Gate blocking a PR — approval required" width="700">
+  <a href="./assets/demo.mp4">
+    <img src="./assets/demo.gif" alt="Deploy Gate: PR blocked → human signs → merge unlocked" width="540">
+  </a>
 </p>
 
 ```
-PR opened → ❌ Blocked → Human signs → ✅ Merge allowed
+PR opened → ❌ Deploy blocked → Human authorizes → ✅ Signed → Merge unlocked
 ```
 
-Open a PR → Deploy Gate blocks it → click approval link → sign → merge proceeds → receipt recorded.
-
 ---
 
 ## Quickstart