Add passkey prompt dismissal and consolidate company admin navigation

- Add "Don't ask me again" to passkey enrollment prompt (PasskeyPromptDismissed
  field on ApplicationUser; DismissPrompt POST action; migration applied)
- Add Subscription & Features button to Companies/Index btn-group and
  Companies/Edit header for direct navigation to SubscriptionManagement/Manage
- Add Edit Company back-link on SubscriptionManagement/Manage
- Remove duplicate AI Features section from Companies/Edit (managed exclusively
  via Subscription & Features page)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Web/Views/Companies/Index.cshtml

@@ -184,6 +184,10 @@
                                                class="btn btn-outline-secondary" title="Edit">
                                                 <i class="bi bi-pencil"></i>
                                             </a>
+                                            <a asp-controller="SubscriptionManagement" asp-action="Manage" asp-route-id="@company.Id"
+                                               class="btn btn-outline-info" title="Manage Subscription & Features">
+                                                <i class="bi bi-credit-card"></i>
+                                            </a>
                                             <form asp-action="ToggleActive" asp-route-id="@company.Id"
                                                   method="post" class="d-inline">
                                                 @Html.AntiForgeryToken()