UI/UX polish: terminal design system alignment pass

Views:
- DashboardView.php: remove hardcoded [ ] from admin-badge button (CSS adds them)
- DashboardView.php: view toggle ≡/▦ → [ = ]/[ # ] (view-btn suppresses auto-brackets)
- DashboardView.php: clear-search ✗ → [ X ] (plain text, no auto-brackets on <a>)
- DashboardView.php: remove ↓ arrow emoji from export button text
- TicketView.php: tab labels → UPPERCASE (tab-btn CSS adds [ ] around text)
- TicketView.php: Edit Ticket/Clone/Add Comment/Add → title-case → UPPERCASE
- TicketView.php: reply button ↩ → [ << ] (comment-action-btn has no auto-brackets)

JavaScript:
- dashboard.js: modal/action button text all → UPPERCASE (CONFIRM/CANCEL/SAVE/ASSIGN/UPDATE/DELETE PERMANENTLY)
- dashboard.js: null guard in loadTemplate(), toggleSelectAll()
- ticket.js: null guards in addDependency(), handleFileUpload()

CSS:
- dashboard.css: z-index 1001/1002 magic numbers → var(--z-modal)/var(--z-popover)
- ticket.css: status-select hover/focus border rgba(white) → terminal palette

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

assets/js/ticket.js

@@ -680,8 +680,11 @@ function renderDependents(dependents) {
 
 function addDependency() {
     const ticketId = window.ticketData.id;
-    const dependsOnId = document.getElementById('dependencyTicketId').value.trim();
-    const dependencyType = document.getElementById('dependencyType').value;
+    const depIdEl = document.getElementById('dependencyTicketId');
+    const depTypeEl = document.getElementById('dependencyType');
+    if (!depIdEl || !depTypeEl) return;
+    const dependsOnId = depIdEl.value.trim();
+    const dependencyType = depTypeEl.value;
 
     if (!dependsOnId) {
         lt.toast.warning('Please enter a ticket ID', 3000);
@@ -705,7 +708,7 @@ function addDependency() {
     .then(data => {
         if (data.success) {
             lt.toast.success('Dependency added', 3000);
-            document.getElementById('dependencyTicketId').value = '';
+            if (depIdEl) depIdEl.value = '';
             loadDependencies();
         } else {
             lt.toast.error('Error: ' + (data.error || 'Unknown error'), 4000);
@@ -806,6 +809,7 @@ function handleFileUpload(files) {
     const progressDiv = document.getElementById('uploadProgress');
     const progressFill = document.getElementById('progressFill');
     const statusText = document.getElementById('uploadStatus');
+    if (!progressDiv || !progressFill || !statusText) return;
 
     let uploadedCount = 0;
     const totalFiles = files.length;