fix: save button not submitting — form id + form= attribute on submit button; migrator connection string in dev compose

- _EditorLayout renders FormActions section outside <form> in the DOM
- Added id='templateForm' to form, form='templateForm' to submit button (HTML5 form association)
- Added migrator env override in docker-compose.Development.yml so connection string is not read from \

Ref: IT-628

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

docker/environments/docker-compose.Development.yml

@@ -1,4 +1,8 @@
 services:
+  migrator:
+    environment:
+      - App__ConnectionString=Host=db;Port=5432;Database=notification_service;Username=postgres;Password=postgres
+
   api:
     environment:
       - ASPNETCORE_ENVIRONMENT=Development