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>

HrynCo.NotificationService.Web/Views/AdminTemplates/Edit.cshtml

@@ -6,7 +6,7 @@
     ViewData["EditorTitle"] = Model.PageTitle;
 }
 
-<form asp-action="Save" asp-controller="AdminTemplates" method="post">
+<form id="templateForm" asp-action="Save" asp-controller="AdminTemplates" method="post">
     @Html.AntiForgeryToken()
     <input asp-for="Id" type="hidden" />
     <input type="hidden" name="IsNew" value="@Model.IsNew" />
@@ -65,7 +65,7 @@
     </div>
 
     @section FormActions {
-        <button type="submit" class="btn btn-primary">💾 Save</button>
+        <button type="submit" form="templateForm" class="btn btn-primary">💾 Save</button>
         <a href="/admin/templates" class="btn btn-secondary">✖ Cancel</a>
     }
 </form>

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