feat: implement admin-users management with super admin restriction

- Add /admin/admin-users routes for managing admin users (super admin only)
- Remove vendor role from user creation form (vendors created via company hierarchy)
- Add admin-users.html and admin-user-detail.html templates
- Add admin-users.js and admin-user-detail.js for frontend logic
- Move database operations to admin_platform_service (list, get, create, delete, toggle status)
- Update sidebar to show Admin Users section only for super admins
- Add isSuperAdmin computed property to init-alpine.js
- Fix /api/v1 prefix issues in JS files (apiClient already adds prefix)
- Update architecture rule JS-012 to catch more variable patterns (url, endpoint, path)
- Replace inline SVGs with $icon() helper in select-platform.html

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

static/admin/js/select-platform.js

@@ -15,6 +15,13 @@ function selectPlatform() {
         async init() {
             platformLog.info('=== PLATFORM SELECTION PAGE INITIALIZING ===');
 
+            // Prevent multiple initializations
+            if (window._platformSelectInitialized) {
+                platformLog.warn('Platform selection page already initialized, skipping...');
+                return;
+            }
+            window._platformSelectInitialized = true;
+
             // Set theme
             this.dark = localStorage.getItem('theme') === 'dark';
 
@@ -36,7 +43,7 @@ function selectPlatform() {
 
             try {
                 platformLog.info('Fetching accessible platforms...');
-                const response = await apiClient.get('/api/v1/admin/auth/accessible-platforms');
+                const response = await apiClient.get('/admin/auth/accessible-platforms');
                 platformLog.debug('Platforms response:', response);
 
                 this.isSuperAdmin = response.is_super_admin;
@@ -83,7 +90,7 @@ function selectPlatform() {
 
             try {
                 const response = await apiClient.post(
-                    `/api/v1/admin/auth/select-platform?platform_id=${platform.id}`
+                    `/admin/auth/select-platform?platform_id=${platform.id}`
                 );
 
                 platformLog.debug('Platform selection response:', response);
@@ -125,25 +132,20 @@ function selectPlatform() {
             }
         },
 
-        logout() {
+        async logout() {
             platformLog.info('Logging out...');
 
-            fetch('/api/v1/admin/auth/logout', {
-                method: 'POST',
-                headers: {
-                    'Authorization': `Bearer ${localStorage.getItem('admin_token')}`
-                }
-            })
-            .catch((error) => {
+            try {
+                await apiClient.post('/admin/auth/logout');
+            } catch (error) {
                 platformLog.error('Logout API error:', error);
-            })
-            .finally(() => {
+            } finally {
                 localStorage.removeItem('admin_token');
                 localStorage.removeItem('admin_user');
                 localStorage.removeItem('admin_platform');
                 localStorage.removeItem('token');
                 window.location.href = '/admin/login';
-            });
+            }
         },
 
         toggleDarkMode() {