Design consistency audit fixes: alerts, cards, dark mode, utilities

Alert sweep (113 alerts, 79 files):
  All persistent static banners now carry alert-permanent so the
  layout's 5-second auto-dismiss cannot swallow guidance, warnings,
  or validation errors. Transient dismissible toasts left untouched.

CSS fixes (site.css):
  .card.shadow-sm      — strips rogue border from ~40 drifted cards
  .card-header.bg-white — rebinds to var(--bs-body-bg) so card
                          headers follow dark/light theme correctly
  Typography utilities  — .text-2xs (.68rem), .text-xs (.73rem)
  Token color classes   — .text-ember, .text-ok, .text-bad,
                          .text-warn, .text-cool, .bg-paper-2
  Layout utilities      — .mw-xs/sm/md/lg replace inline max-width
  Comment              — documents text-ember vs text-primary intent

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

src/PowderCoating.Web/Views/EmailBroadcast/Preview.cshtml

@@ -1,4 +1,4 @@
-@using PowderCoating.Web.Controllers
+@using PowderCoating.Web.Controllers
 @model AdminEmailPreviewModel
 @{
     ViewData["Title"] = "Preview Admin Email";
@@ -46,7 +46,7 @@
             <div class="card shadow-sm border-0 mb-4">
                 <div class="card-header bg-transparent fw-semibold py-3">Delivery Summary</div>
                 <div class="card-body">
-                    <div class="alert alert-info mb-0">
+                    <div class="alert alert-info alert-permanent mb-0">
                         The system will process each selected company one at a time.
                         The sample shown on the left uses the first available recipient after token replacement.
                     </div>
@@ -78,7 +78,7 @@
                                     <div class="small text-muted">@(string.IsNullOrWhiteSpace(row.RecipientEmail) ? "No primary contact email configured" : row.RecipientEmail)</div>
                                 </td>
                                 <td>
-                                    <div>@(string.IsNullOrWhiteSpace(row.CompanyAdminName) ? "—" : row.CompanyAdminName)</div>
+                                    <div>@(string.IsNullOrWhiteSpace(row.CompanyAdminName) ? "—" : row.CompanyAdminName)</div>
                                     @if (!string.IsNullOrWhiteSpace(row.CompanyAdminEmail))
                                     {
                                         <div class="small text-muted">@row.CompanyAdminEmail</div>