fix: minor fixes and template updates

- seed_demo.py: Change company owner role from "user" to "vendor"
- header.html: Update header partial styling/content
- marketplace.js: Minor JS updates
- marketplace.html: Template updates

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

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

static/admin/js/marketplace.js

@@ -58,23 +58,35 @@ function adminMarketplace() {
         autoRefreshInterval: null,
 
         async init() {
+            adminMarketplaceLog.info('Marketplace init() called');
+
             // Guard against multiple initialization
             if (window._adminMarketplaceInitialized) {
+                adminMarketplaceLog.warn('Already initialized, skipping');
                 return;
             }
             window._adminMarketplaceInitialized = true;
 
-            // IMPORTANT: Call parent init first
-            const parentInit = data().init;
-            if (parentInit) {
-                await parentInit.call(this);
+            // Ensure form defaults are set (in case spread didn't work)
+            if (!this.importForm.marketplace) {
+                this.importForm.marketplace = 'Letzshop';
             }
+            if (!this.importForm.batch_size) {
+                this.importForm.batch_size = 1000;
+            }
+            if (!this.importForm.language) {
+                this.importForm.language = 'fr';
+            }
+
+            adminMarketplaceLog.info('Form defaults:', this.importForm);
 
             await this.loadVendors();
             await this.loadJobs();
 
             // Auto-refresh active jobs every 10 seconds
             this.startAutoRefresh();
+
+            adminMarketplaceLog.info('Marketplace initialization complete');
         },
 
         /**