Implement complete API routes and mock authentication for full CMS functionality

- Add comprehensive nested route structure with proper authentication layers
- Implement UpdateContent and ReorderCollectionItems handlers with repository pattern
- Add automatic mock JWT token fetching for seamless development workflow
- Restore content editing and collection reordering functionality broken after database refactoring
- Provide production-ready authentication architecture with development convenience
- Enable full CMS operations in browser with proper CRUD and bulk transaction support

internal/db/sqlite_repository.go

@@ -269,6 +269,54 @@ func (r *SQLiteRepository) CreateCollectionItemAtomic(ctx context.Context, siteI
 	return nil, fmt.Errorf("CreateCollectionItemAtomic not yet implemented for SQLite")
 }
 
+// UpdateContent updates an existing content item
+func (r *SQLiteRepository) UpdateContent(ctx context.Context, siteID, contentID, htmlContent, lastEditedBy string) (*ContentItem, error) {
+	content, err := r.queries.UpdateContent(ctx, sqlite.UpdateContentParams{
+		HtmlContent:  htmlContent,
+		LastEditedBy: lastEditedBy,
+		ID:           contentID,
+		SiteID:       siteID,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return &ContentItem{
+		ID:               content.ID,
+		SiteID:           content.SiteID,
+		HTMLContent:      content.HtmlContent,
+		OriginalTemplate: FromNullString(content.OriginalTemplate),
+		UpdatedAt:        fmt.Sprintf("%d", content.UpdatedAt),
+		LastEditedBy:     content.LastEditedBy,
+	}, nil
+}
+
+// ReorderCollectionItems reorders collection items in bulk
+func (r *SQLiteRepository) ReorderCollectionItems(ctx context.Context, siteID, collectionID string, items []CollectionItemPosition, lastEditedBy string) error {
+	// Use transaction for atomic bulk updates
+	tx, err := r.db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	qtx := r.queries.WithTx(tx)
+	for _, item := range items {
+		err = qtx.UpdateCollectionItemPosition(ctx, sqlite.UpdateCollectionItemPositionParams{
+			ItemID:       item.ItemID,
+			CollectionID: collectionID,
+			SiteID:       siteID,
+			Position:     int64(item.Position),
+			LastEditedBy: lastEditedBy,
+		})
+		if err != nil {
+			return fmt.Errorf("failed to update position for item %s: %w", item.ItemID, err)
+		}
+	}
+
+	return tx.Commit()
+}
+
 // WithTransaction executes a function within a database transaction
 func (r *SQLiteRepository) WithTransaction(ctx context.Context, fn func(ContentRepository) error) error {
 	tx, err := r.db.BeginTx(ctx, nil)