add video limk

Author: erights

README.md

@@ -22,7 +22,7 @@ Champions:
 
 - ***Stage 2.7 Status Update*** - July 2025 Plenary ([slides.key](./no-stamping-talks/non-extensible-applies-to-private-update.key), [slides.pdf](./no-stamping-talks/non-extensible-applies-to-private-update.pdf), [video](https://www.youtube.com/watch?v=kFBvqdQOjQ8&list=PLzDw4TTug5O3vIAd4IR1Gp5t_46co_dv9&index=28))
 
-- ***for Stage 3*** - September 2025 Plenary ([slices.key](./no-stamping-talks/non-extensible-applies-to-private-for-s3.key), [slides.pdf](./no-stamping-talks/non-extensible-applies-to-private-for-s3.pdf))
+- ***for Stage 3*** - September 2025 Plenary ([slices.key](./no-stamping-talks/non-extensible-applies-to-private-for-s3.key), [slides.pdf](./no-stamping-talks/non-extensible-applies-to-private-for-s3.pdf), [video](https://www.youtube.com/watch?v=IPFCoSXvahw&list=PLzDw4TTug5O3vIAd4IR1Gp5t_46co_dv9&index=30))
 
 ## Background