fix: resolve homepage sections editor and rendering issues

- Fix sections editor not showing by converting isHomepage getter to property
- Add Alpine Collapse plugin for accordion animations
- Fix Quill editor content not syncing after page load
- Add platform dropdown to content page edit form
- Create shared templates config (app/templates_config.py) with i18n globals
  to make _() translation function available in Jinja2 macros
- Fix pricing template field names (monthly_price → price_monthly)
- Fix translation key (pricing.save_20 → pricing.save_months)
- Add tiers context to CMS homepage route for pricing section
- Fix architecture validation issues (language defaults, inline SVGs → $icon)

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

static/admin/js/content-page-edit.js

@@ -30,10 +30,13 @@ function contentPageEditor(pageId) {
             show_in_footer: true,
             show_in_legal: false,
             display_order: 0,
+            platform_id: null,
             vendor_id: null
         },
+        platforms: [],
         vendors: [],
         loading: false,
+        loadingPlatforms: false,
         loadingVendors: false,
         saving: false,
         error: null,
@@ -96,8 +99,8 @@ function contentPageEditor(pageId) {
             }
             window._contentPageEditInitialized = true;
 
-            // Load vendors for dropdown
-            await this.loadVendors();
+            // Load platforms and vendors for dropdowns
+            await Promise.all([this.loadPlatforms(), this.loadVendors()]);
 
             if (this.pageId) {
                 // Edit mode - load existing page
@@ -117,9 +120,34 @@ function contentPageEditor(pageId) {
             contentPageEditLog.info('=== CONTENT PAGE EDITOR INITIALIZATION COMPLETE ===');
         },
 
-        // Check if we should show section editor
-        get isHomepage() {
-            return this.form.slug === 'home';
+        // Check if we should show section editor (property, not getter for Alpine compatibility)
+        isHomepage: false,
+
+        // Update isHomepage when slug changes
+        updateIsHomepage() {
+            this.isHomepage = this.form.slug === 'home';
+        },
+
+        // Load platforms for dropdown
+        async loadPlatforms() {
+            this.loadingPlatforms = true;
+            try {
+                contentPageEditLog.info('Loading platforms...');
+                const response = await apiClient.get('/admin/platforms?is_active=true');
+                const data = response.data || response;
+                this.platforms = data.platforms || data.items || data || [];
+                contentPageEditLog.info(`Loaded ${this.platforms.length} platforms`);
+
+                // Set default platform if not editing and no platform selected
+                if (!this.pageId && !this.form.platform_id && this.platforms.length > 0) {
+                    this.form.platform_id = this.platforms[0].id;
+                }
+            } catch (err) {
+                contentPageEditLog.error('Error loading platforms:', err);
+                this.platforms = [];
+            } finally {
+                this.loadingPlatforms = false;
+            }
         },
 
         // Load vendors for dropdown
@@ -170,11 +198,19 @@ function contentPageEditor(pageId) {
                     show_in_footer: page.show_in_footer !== undefined ? page.show_in_footer : true,
                     show_in_legal: page.show_in_legal || false,
                     display_order: page.display_order || 0,
+                    platform_id: page.platform_id,
                     vendor_id: page.vendor_id
                 };
 
                 contentPageEditLog.info('Page loaded successfully');
 
+                // Update computed properties after loading
+                this.updateIsHomepage();
+
+                // Re-initialize Quill editor content after page data is loaded
+                // (Quill may have initialized before loadPage completed)
+                this.syncQuillContent();
+
             } catch (err) {
                 contentPageEditLog.error('Error loading page:', err);
                 this.error = err.message || 'Failed to load page';
@@ -183,6 +219,26 @@ function contentPageEditor(pageId) {
             }
         },
 
+        // Sync Quill editor content after page data loads
+        // Quill may initialize before loadPage completes, leaving editor empty
+        syncQuillContent(retries = 5) {
+            const quillContainer = document.getElementById('content-editor');
+
+            if (!quillContainer || !quillContainer.__quill) {
+                // Quill not ready yet, retry
+                if (retries > 0) {
+                    setTimeout(() => this.syncQuillContent(retries - 1), 100);
+                }
+                return;
+            }
+
+            const quill = quillContainer.__quill;
+            if (this.form.content && quill.root.innerHTML !== this.form.content) {
+                quill.root.innerHTML = this.form.content;
+                contentPageEditLog.debug('Synced Quill content after page load');
+            }
+        },
+
         // ========================================
         // HOMEPAGE SECTIONS METHODS
         // ========================================
@@ -355,6 +411,7 @@ function contentPageEditor(pageId) {
                     show_in_footer: this.form.show_in_footer,
                     show_in_legal: this.form.show_in_legal,
                     display_order: this.form.display_order,
+                    platform_id: this.form.platform_id,
                     vendor_id: this.form.vendor_id
                 };