Add Koala identify tracking to newsletter signup

- Add rx.call_script to trigger ko.identify() after successful email validation
- Integrates with existing Koala pixel infrastructure
- Maintains existing newsletter signup functionality
- Returns both Koala identify call and success toast message

Co-Authored-By: Alek <[email protected]>

Author: devin-ai-integration[bot]

pcweb/signup.py

@@ -100,4 +100,7 @@ def signup(
         self.send_contact_to_webhook(email)
         self.add_contact_to_loops(email)
         self.signed_up = True
-        return rx.toast.success("Thanks for signing up to the Newsletter!")
+        return [
+            rx.call_script(f"ko.identify('{email}')"),
+            rx.toast.success("Thanks for signing up to the Newsletter!")
+        ]