gallery changes

Hero gallery: the slideshow on Home doesn’t open full screen. Only portfolio images do, as you asked.
Lightbox: it has no pinch-zoom.
Delete: removing an image still has no confirm step, same as before.
New dependency: drag-and-drop uses @dnd-kit, which I added to package.json.
Touch dragging: I couldn’t test it on a real phone. Mouse and keyboard dragging work.
Health test: src/app/api/health/__tests__/route.test.ts passes, but it prints unhandled rejections. Its prisma mock has no notificationDelivery, so getQueueHealth throws. That comes from the earlier “Remaining features” commit and I left it alone. It’s a quick fix if you want it.

src/services/gallery/__tests__/gallery.service.integration.test.ts

@@ -3,8 +3,10 @@ import { GalleryPlacement } from "@/generated/prisma/enums";
 import {
   addGalleryImage,
   deleteGalleryImage,
+  GALLERY_IMAGE_URL_MAX_LENGTH,
   listGalleryImages,
   reorderGalleryImages,
+  replaceGalleryImage,
   updateGalleryImage,
 } from "@/services/gallery/gallery.service";
 import { cleanupTestBusiness, createTestBusiness, prisma } from "@/services/scheduling/__tests__/fixtures";
@@ -83,4 +85,46 @@ describe("Gallery service (integration)", () => {
     expect(result.success).toBe(true);
     expect(await prisma.businessGalleryImage.findUnique({ where: { id: image.id } })).toBeNull();
   });
+
+  describe("replacing an image", () => {
+    const add = (url: string, extra: { category?: string } = {}) =>
+      addGalleryImage(prisma, { businessId: business.businessId, placement: GalleryPlacement.PORTFOLIO, imageUrl: url, ...extra });
+
+    it("swaps the picture but keeps its position, category, caption and visibility", async () => {
+      const first = await add("/media/first.png");
+      const middle = await add("/media/middle.png", { category: "Fades" });
+      const last = await add("/media/last.png");
+      await updateGalleryImage(prisma, { id: middle.id, businessId: business.businessId, caption: "Client X", isActive: false });
+
+      const result = await replaceGalleryImage(prisma, { id: middle.id, businessId: business.businessId, imageUrl: "/media/new.png" });
+
+      expect(result).toEqual({ success: true });
+      const all = await listGalleryImages(prisma, { businessId: business.businessId, placement: GalleryPlacement.PORTFOLIO });
+      expect(all.map((i) => i.id)).toEqual([first.id, middle.id, last.id]);
+      expect(all[1]).toMatchObject({ imageUrl: "/media/new.png", category: "Fades", caption: "Client X", isActive: false });
+    });
+
+    it("refuses an empty or over-long address, leaving the picture as it was", async () => {
+      const image = await add("/media/keep.png");
+
+      for (const imageUrl of ["   ", "x".repeat(GALLERY_IMAGE_URL_MAX_LENGTH + 1)]) {
+        const result = await replaceGalleryImage(prisma, { id: image.id, businessId: business.businessId, imageUrl });
+        expect(result.success).toBe(false);
+      }
+      expect((await prisma.businessGalleryImage.findUniqueOrThrow({ where: { id: image.id } })).imageUrl).toBe("/media/keep.png");
+    });
+
+    it("can't replace another business's image", async () => {
+      const otherBusiness = await createTestBusiness();
+      try {
+        const image = await add("/media/mine.png");
+        const result = await replaceGalleryImage(prisma, { id: image.id, businessId: otherBusiness.businessId, imageUrl: "/media/hijack.png" });
+
+        expect(result.success).toBe(false);
+        expect((await prisma.businessGalleryImage.findUniqueOrThrow({ where: { id: image.id } })).imageUrl).toBe("/media/mine.png");
+      } finally {
+        await cleanupTestBusiness(otherBusiness);
+      }
+    });
+  });
 });