docs(transition): add warning banner about v1 deprecation and legacy dashboard

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: VinciGit00

transition-from-v1-to-v2.mdx

@@ -5,6 +5,10 @@ description: Move from v1 to v2 quickly and safely
 
 ## Transition from v1 to v2
 
+<Warning>
+  Once you log in, your v1 code will be deprecated. The legacy dashboard at [dashboard.scrapegraphai.com/login](https://dashboard.scrapegraphai.com/login/) will remain temporarily available during the transition.
+</Warning>
+
 If you are coming from the legacy v1 docs, use this page as your migration checkpoint.
 
 Before anything else, log in to the dashboard at [scrapegraphai.com/login](https://scrapegraphai.com/login).