feat: multi-module improvements across merchant, store, i18n, and customer systems

- Fix platform-grouped merchant sidebar menu with core items at root level
- Add merchant store management (detail page, create store, team page)
- Fix store settings 500 error by removing dead stripe/API tab
- Move onboarding translations to module-owned locale files
- Fix onboarding banner i18n with server-side rendering + context inheritance
- Refactor login language selectors to use languageSelector() function (LANG-002)
- Move HTTPException handling to global exception handler in merchant routes (API-003)
- Add language selector to all login pages and portal headers
- Fix customer module: drop order stats from customer model, add to orders module
- Fix admin menu config visibility for super admin platform context
- Fix storefront auth and layout issues
- Add missing i18n translations for onboarding steps (en/fr/de/lb)

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

app/modules/tenancy/static/admin/js/select-platform.js

@@ -1,5 +1,5 @@
 // static/admin/js/select-platform.js
-// Platform selection page for platform admins
+// Platform selection page for admins (platform admins and super admins)
 
 const platformLog = window.LogConfig ? window.LogConfig.createLogger('PLATFORM_SELECT') : console;
 
@@ -11,6 +11,7 @@ function selectPlatform() {
         error: null,
         platforms: [],
         isSuperAdmin: false,
+        currentPlatformId: null,
 
         async init() {
             platformLog.info('=== PLATFORM SELECTION PAGE INITIALIZING ===');
@@ -46,21 +47,14 @@ function selectPlatform() {
                 const response = await apiClient.get('/admin/auth/accessible-platforms');
                 platformLog.debug('Platforms response:', response);
 
-                this.isSuperAdmin = response.role === 'super_admin';
+                this.isSuperAdmin = response.is_super_admin === true;
                 this.platforms = response.platforms || [];
+                this.currentPlatformId = response.current_platform_id || null;
 
-                if (this.isSuperAdmin) {
-                    platformLog.info('User is super admin, redirecting to dashboard...');
-                    setTimeout(() => {
-                        window.location.href = '/admin/dashboard';
-                    }, 1500);
-                    return;
-                }
-
-                if (!response.requires_platform_selection && this.platforms.length === 1) {
+                if (!this.isSuperAdmin && !response.requires_platform_selection && this.platforms.length === 1) {
                     // Only one platform assigned, auto-select it
                     platformLog.info('Single platform assigned, auto-selecting...');
-                    await this.selectPlatform(this.platforms[0]);
+                    await this.choosePlatform(this.platforms[0]);
                     return;
                 }
 
@@ -81,7 +75,11 @@ function selectPlatform() {
             }
         },
 
-        async selectPlatform(platform) {
+        isCurrentPlatform(platform) {
+            return this.currentPlatformId && this.currentPlatformId === platform.id;
+        },
+
+        async choosePlatform(platform) {
             if (this.selecting) return;
 
             this.selecting = true;
@@ -132,6 +130,37 @@ function selectPlatform() {
             }
         },
 
+        async deselectPlatform() {
+            if (this.selecting) return;
+
+            this.selecting = true;
+            this.error = null;
+            platformLog.info('Deselecting platform (returning to global mode)...');
+
+            try {
+                const response = await apiClient.post('/admin/auth/deselect-platform');
+
+                if (response.access_token) {
+                    // Store new token without platform context
+                    localStorage.setItem('admin_token', response.access_token);
+                    localStorage.setItem('token', response.access_token);
+
+                    // Remove platform info
+                    localStorage.removeItem('admin_platform');
+
+                    platformLog.info('Platform deselected, redirecting to dashboard...');
+                    window.location.href = '/admin/dashboard';
+                } else {
+                    throw new Error('No token received from server');
+                }
+
+            } catch (error) {
+                platformLog.error('Platform deselection failed:', error);
+                this.error = error.message || 'Failed to deselect platform. Please try again.';
+                this.selecting = false;
+            }
+        },
+
         async logout() {
             platformLog.info('Logging out...');