Add design approval workflow and per-image dimension tracking

- Add DesignApproval and DesignApprovalMessage models for design review workflow
- Add design approval admin interface (list, detail, chat, approve/reject)
- Add per-image dimension tracking to OrderItem
- Add design submission API endpoint
- Add AdminDesignEditor for admin-side design modifications
- Add DesignApprovalChat component for customer-admin communication
- Update design specification generation with image dimension details
- Add design persistence across login with next parameter redirect
- Add font properties UI with font size and color display

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

prisma/migrations/20260718113139_add_reference_size_fields/migration.sql

@@ -0,0 +1,3 @@
+-- AlterTable
+ALTER TABLE "Product" ADD COLUMN     "referenceHeightCm" INTEGER,
+ADD COLUMN     "referenceWidthCm" INTEGER;

prisma/migrations/20260718115108_add_design_dimensions/migration.sql

@@ -0,0 +1,3 @@
+-- AlterTable
+ALTER TABLE "OrderItem" ADD COLUMN     "designHeightCm" DOUBLE PRECISION,
+ADD COLUMN     "designWidthCm" DOUBLE PRECISION;

prisma/migrations/20260718131141_add_design_approval_workflow/migration.sql

@@ -0,0 +1,42 @@
+-- CreateTable
+CREATE TABLE "DesignApproval" (
+    "id" TEXT NOT NULL,
+    "customerId" TEXT,
+    "customerEmail" TEXT NOT NULL,
+    "customerName" TEXT,
+    "productId" TEXT NOT NULL,
+    "designJson" TEXT NOT NULL,
+    "designPreviewUrl" TEXT NOT NULL,
+    "designPreviewUrlBack" TEXT,
+    "placementPreviewUrl" TEXT,
+    "placementPreviewUrlBack" TEXT,
+    "designWidthCm" DOUBLE PRECISION,
+    "designHeightCm" DOUBLE PRECISION,
+    "color" TEXT NOT NULL,
+    "size" TEXT,
+    "status" TEXT NOT NULL DEFAULT 'PENDING',
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "DesignApproval_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "DesignApprovalMessage" (
+    "id" TEXT NOT NULL,
+    "designId" TEXT NOT NULL,
+    "sender" TEXT NOT NULL,
+    "body" TEXT NOT NULL,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "DesignApprovalMessage_pkey" PRIMARY KEY ("id")
+);
+
+-- AddForeignKey
+ALTER TABLE "DesignApproval" ADD CONSTRAINT "DesignApproval_customerId_fkey" FOREIGN KEY ("customerId") REFERENCES "Customer"("id") ON DELETE SET NULL ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "DesignApproval" ADD CONSTRAINT "DesignApproval_productId_fkey" FOREIGN KEY ("productId") REFERENCES "Product"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "DesignApprovalMessage" ADD CONSTRAINT "DesignApprovalMessage_designId_fkey" FOREIGN KEY ("designId") REFERENCES "DesignApproval"("id") ON DELETE CASCADE ON UPDATE CASCADE;

prisma/migrations/20260718133544_add_per_image_dimensions/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "DesignApproval" ADD COLUMN     "designImageDimensions" TEXT;

prisma/migrations/20260718134319_add_image_dimensions_to_order/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "OrderItem" ADD COLUMN     "designImageDimensions" TEXT;