Fix mobile bottom nav consistency and ticket view width

Mobile bottom nav:
- Added nav-label class to all text labels in JS
- Fixed icon sizing (20px fixed height)
- Fixed label sizing (10px for all)
- Equal width columns (25% each)
- Changed gear emoji from ⚙️ to ⚙ for consistency

Ticket view mobile:
- Removed all borders from ticket container
- Removed decorative corners on mobile
- Reduced nested padding significantly
- ascii-frame-inner now 0.75rem padding (was 1rem)
- Nested ascii-frame-inner only 0.5rem
- detail-group full-width has no padding
- Content goes edge-to-edge

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

assets/js/dashboard.js

@@ -95,19 +95,19 @@ function initMobileSidebar() {
         nav.innerHTML = `
             <a href="/">
                 <span class="nav-icon">🏠</span>
-                <span>Home</span>
+                <span class="nav-label">Home</span>
             </a>
             <button type="button" data-action="open-mobile-sidebar">
                 <span class="nav-icon">🔍</span>
-                <span>Filter</span>
+                <span class="nav-label">Filter</span>
             </button>
             <a href="/ticket/create">
                 <span class="nav-icon">➕</span>
-                <span>New</span>
+                <span class="nav-label">New</span>
             </a>
             <button type="button" data-action="open-settings-modal">
-                <span class="nav-icon">⚙️</span>
-                <span>Settings</span>
+                <span class="nav-icon">⚙</span>
+                <span class="nav-label">Settings</span>
             </button>
         `;
         document.body.appendChild(nav);