fix: Implement empty AddVariantCollectionsAndSalesLedger migration

- Added VariantCollectionId and VariantsJson columns to Products table
- Migration was previously empty causing schema mismatch on startup
- Fixes "SQLite Error 1: 'no such column: p.VariantCollectionId'"

The migration file was scaffolded but never implemented, causing production
deployments to fail with database schema errors.

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

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

LittleShop/Migrations/20250928014850_AddVariantCollectionsAndSalesLedger.cs

@@ -10,13 +10,31 @@ namespace LittleShop.Migrations
         /// <inheritdoc />
         protected override void Up(MigrationBuilder migrationBuilder)
         {
+            // Add variant columns to Products table
+            migrationBuilder.AddColumn<Guid?>(
+                name: "VariantCollectionId",
+                table: "Products",
+                type: "TEXT",
+                nullable: true);
 
+            migrationBuilder.AddColumn<string>(
+                name: "VariantsJson",
+                table: "Products",
+                type: "TEXT",
+                nullable: true);
         }
 
         /// <inheritdoc />
         protected override void Down(MigrationBuilder migrationBuilder)
         {
+            // Remove variant columns from Products table
+            migrationBuilder.DropColumn(
+                name: "VariantCollectionId",
+                table: "Products");
 
+            migrationBuilder.DropColumn(
+                name: "VariantsJson",
+                table: "Products");
         }
     }
 }

LittleShop/Migrations/20250928014851_FixVariantColumnsForProducts.sql

@@ -0,0 +1,8 @@
+-- Migration: Fix Variant Columns for Products
+-- Date: 2025-09-28
+-- Description: Adds missing VariantCollectionId and VariantsJson columns to Products table
+--              This fixes the empty AddVariantCollectionsAndSalesLedger migration
+
+-- Add variant columns to Products table
+ALTER TABLE Products ADD COLUMN VariantCollectionId TEXT NULL;
+ALTER TABLE Products ADD COLUMN VariantsJson TEXT NULL;