Add invoice SMS notifications and customer intake kiosk

Invoice SMS:
- Send Invoice modal now prompts Email/SMS/Both based on customer contact data
- New /invoice/{token} customer-facing view page with full line items and pay button
- PublicViewToken (permanent) added to Invoice; separate from expiring PaymentLinkToken
- InvoiceSent SMS default template added; customizable via Notification Templates settings
- {{viewUrl}} placeholder documented in template editor

Customer Intake Kiosk:
- Tablet kiosk flow: Contact → Job → Terms/Signature → Confirmation
- Remote link mode for off-site customers (lighter form, no signature)
- KioskHub (AllowAnonymous SignalR) for staff-to-tablet push without login
- Staff activates tablet via cookie; sends remote link manually
- Submitted sessions create Customer + Job automatically; fires in-app notification

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

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

@@ -33,6 +33,14 @@
                 </p>
                 <div class="d-flex gap-2 flex-wrap align-items-center">
                     <a asp-controller="Jobs" asp-action="Board" class="btn btn-sm btn-primary">Open Jobs Board</a>
+                    <button type="button" class="btn btn-sm btn-outline-info" id="btnStartIntake"
+                            title="Push the intake form to the front-desk tablet">
+                        <i class="bi bi-tablet me-1"></i>Start Intake
+                    </button>
+                    <a href="/Kiosk/SendRemoteLink" class="btn btn-sm btn-outline-secondary"
+                       title="Email a customer a link to fill out the intake form on their own device">
+                        <i class="bi bi-envelope-at me-1"></i>Remote Link
+                    </a>
                     @if (!string.IsNullOrEmpty(Model.TipOfTheDay))
                     {
                         <span class="text-muted d-none d-xl-inline" style="font-size:0.73rem;"><i class="bi bi-lightbulb me-1"></i>@Model.TipOfTheDay</span>
@@ -827,6 +835,40 @@
 @section Scripts {
 <script src="~/js/shop-progress-widget.js" asp-append-version="true"></script>
 <script>
+    // Start Intake — pushes SignalR event to front-desk tablet
+    document.getElementById('btnStartIntake')?.addEventListener('click', async function () {
+        const btn   = this;
+        const token = document.querySelector('input[name="__RequestVerificationToken"]')?.value;
+        btn.disabled = true;
+        btn.innerHTML = '<span class="spinner-border spinner-border-sm me-1"></span>Sending…';
+        try {
+            const res = await fetch('/Kiosk/StartSession', {
+                method: 'POST',
+                headers: { 'RequestVerificationToken': token, 'Content-Type': 'application/json' }
+            });
+            const data = await res.json();
+            if (data.success) {
+                btn.innerHTML = '<i class="bi bi-check-circle me-1"></i>Sent!';
+                btn.classList.replace('btn-outline-info', 'btn-success');
+                setTimeout(() => {
+                    btn.disabled = false;
+                    btn.innerHTML = '<i class="bi bi-tablet me-1"></i>Start Intake';
+                    btn.classList.replace('btn-success', 'btn-outline-info');
+                }, 3000);
+            } else {
+                throw new Error('Server returned failure');
+            }
+        } catch (err) {
+            btn.innerHTML = '<i class="bi bi-exclamation-triangle me-1"></i>Failed';
+            btn.classList.replace('btn-outline-info', 'btn-outline-danger');
+            setTimeout(() => {
+                btn.disabled = false;
+                btn.innerHTML = '<i class="bi bi-tablet me-1"></i>Start Intake';
+                btn.classList.replace('btn-outline-danger', 'btn-outline-info');
+            }, 3000);
+        }
+    });
+
     // Powder Orders - Mark as Ordered
     document.querySelectorAll('.mark-ordered-btn').forEach(btn => {
         btn.addEventListener('click', async function () {