Button consistency sweep + mobile responsiveness patches

- Standardize modal dismiss/cancel buttons to btn-outline-secondary across 70+ views
- Remove btn-sm from page-level Create and Back buttons (Index + Detail pages)
- Fix Edit buttons on Details pages: btn-secondary -> btn-warning
- Fix form Cancel/Back links: btn-secondary -> btn-outline-secondary
- Add 10 CSS patches to site.css for mobile/tablet responsiveness:
  top-navbar overflow prevention, page-header flex-wrap at 575px,
  table action button min-height override, notification dropdown width cap,
  tablet content padding

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

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

@@ -1,4 +1,4 @@
-@model List<PowderCoating.Core.Entities.Company>
+@model List<PowderCoating.Core.Entities.Company>
 @{
     ViewData["Title"] = "Seed Data Management";
     ViewData["PageIcon"] = "bi-database-fill-gear";
@@ -196,7 +196,7 @@
                     </table>
                 </div>
 
-                <!-- Mobile card view — shown on screens < 992px -->
+                <!-- Mobile card view — shown on screens < 992px -->
                 <div class="mobile-card-view d-lg-none">
                     <div class="mobile-card-list">
                         @foreach (var company in Model)
@@ -363,7 +363,7 @@
                     </div>
                 </div>
                 <div class="modal-footer">
-                    <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Cancel</button>
+                    <button type="button" class="btn btn-outline-secondary" data-bs-dismiss="modal">Cancel</button>
                     <button type="submit" class="btn btn-warning" id="unseedSubmitBtn" disabled>
                         <i class="bi bi-database-fill-dash me-1"></i>Remove Selected Data
                     </button>