Restore all zeroed views + add bulk gift certificate creation

The HTML entity sweep script had a bug where it wrote empty files for any
view that contained no target Unicode characters, zeroing out 215 view files.
All views restored from the pre-sweep commit (cefdf3e).

Bulk gift certificate feature:
- BulkCreateGiftCertificateDto with Quantity (1-500), Amount, Reason, Expiry, Notes
- GenerateBulkGiftCertificatePdfAsync on IPdfService / PdfService: one Letter page
  per cert, reusing the same purple/gold branded ComposeGiftCertificateContent helper
- GiftCertificatesController: BulkCreate GET/POST, BulkResult GET, BulkDownloadPdf POST
- Views: BulkCreate.cshtml (form with live total preview), BulkResult.cshtml (table +
  Download All PDF button that POSTs cert IDs to avoid URL length limits)
- gift-certificate-bulk.js: live preview + spinner/disable on submit
- Index.cshtml: Bulk Create button added alongside New Certificate

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

src/PowderCoating.Web/Views/Kiosk/Welcome.cshtml

@@ -0,0 +1,33 @@
+@{
+    Layout = "~/Views/Shared/_KioskLayout.cshtml";
+    ViewData["Title"] = "Welcome";
+    ViewBag.HideLayoutLogo = true;
+}
+
+<div id="kiosk-welcome-root"
+     data-company-id="@ViewBag.CompanyId"
+     class="kiosk-welcome-screen">
+
+    @if (!string.IsNullOrEmpty(ViewBag.CompanyLogoUrl as string))
+    {
+        <img src="@ViewBag.CompanyLogoUrl"
+             alt="@ViewBag.CompanyName"
+             class="kiosk-welcome-logo" />
+    }
+    else
+    {
+        <h1 class="kiosk-welcome-title">@ViewBag.CompanyName</h1>
+    }
+
+    <p class="kiosk-welcome-subtitle">Welcome! A staff member will start your intake shortly.</p>
+
+    <div class="kiosk-idle-indicator">
+        <span id="kiosk-conn-dot" style="display:inline-block;width:10px;height:10px;
+              border-radius:50%;background:#94a3b8;margin-right:6px;transition:background 0.3s;"></span>
+        <span id="kiosk-conn-label">Connecting…</span>
+    </div>
+</div>
+
+@section Scripts {
+    <script src="~/js/kiosk-welcome.js"></script>
+}