fix: Update all navigation links to point to new admin import system

PROBLEM FIXED:
- Main menu "Import" was still pointing to old unified-import system
- Dashboard quick actions pointed to broken import routes
- Keyboard shortcut Alt+I was routing to old system

NAVIGATION UPDATES:
✅ Desktop/Mobile nav menu: /import → /admin/import
✅ Dashboard quick action button: /import → /admin/import
✅ Dashboard "Open Import" link: /import → /admin/import
✅ Keyboard shortcut Alt+I: /import → /admin/import
✅ Support modal page mapping: /import → /admin/import
✅ Base template page names: /import → /admin/import

ADMIN PERMISSIONS:
- Import menu items now properly hidden by default
- Shown only to admin users via JavaScript permission check
- Maintains security for admin-only functionality

REMOVED REFERENCES:
- All /flexible route references (old flexible import system)
- Cleaned up navigation menu from removed functionality

NOW WORKING:
- Clicking "Import" in main menu → new /admin/import interface
- Alt+I keyboard shortcut → new /admin/import interface
- Dashboard import button → new /admin/import interface
- All navigation properly secured for admin users only

🤖 Generated with [Claude Code](https://claude.ai/code)

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

static/js/keyboard-shortcuts.js

@@ -57,7 +57,7 @@ function handleKeyboardShortcuts(event) {
             break;
         case 'Alt+I':
             event.preventDefault();
-            navigateTo('/import');
+            navigateTo('/admin/import');
             break;
         case 'Alt+A':
             event.preventDefault();

static/js/main.js

@@ -475,7 +475,11 @@ async function checkUserPermissions() {
                 const adminDivider = document.getElementById('admin-menu-divider');
                 if (adminItem) adminItem.classList.remove('hidden');
                 if (adminDivider) adminDivider.classList.remove('hidden');
-                // Import navigation items removed
+                // Show import menu for admins
+                const importDesktop = document.getElementById('nav-import-desktop');
+                const importMobile = document.getElementById('nav-import-mobile');
+                if (importDesktop) importDesktop.classList.remove('hidden');
+                if (importMobile) importMobile.classList.remove('hidden');
             }
             const userDropdownName = document.querySelector('#userDropdown button span');
             if (user.full_name && userDropdownName) {