fix(admin): return presignedUrl from from-url endpoint and update image preview after fetch

- images.ts: import getImageUrl from storage service, call after fetchImageFromUrl and include presignedUrl in response
- $itemId.tsx: update handleFetchFromUrl to use presignedUrl and dominantColor from response, set imageUrl in form state so ImageUpload component shows preview immediately

src/client/routes/admin/items/$itemId.tsx

@@ -161,13 +161,17 @@ function AdminItemEditPage() {
 		setFetchingImage(true);
 		setFetchError(null);
 		try {
-			const result = await apiPost<{ filename: string; sourceUrl: string }>(
-				"/api/images/from-url",
-				{ url: fetchUrl.trim() },
-			);
+			const result = await apiPost<{
+				filename: string;
+				sourceUrl: string;
+				presignedUrl: string;
+				dominantColor: string | null;
+			}>("/api/images/from-url", { url: fetchUrl.trim() });
 			setForm((prev) => ({
 				...prev,
 				imageFilename: result.filename,
+				imageUrl: result.presignedUrl,
+				dominantColor: result.dominantColor ?? "",
 				imageSourceUrl: fetchUrl.trim(),
 			}));
 			setFetchUrl("");

src/server/routes/images.ts

@@ -6,7 +6,7 @@ import {
 	extractDominantColor,
 	fetchImageFromUrl,
 } from "../services/image.service";
-import { uploadImage } from "../services/storage.service";
+import { getImageUrl, uploadImage } from "../services/storage.service";
 
 const ALLOWED_TYPES = ["image/jpeg", "image/png", "image/webp"];
 const MAX_SIZE = 5 * 1024 * 1024; // 5MB
@@ -19,7 +19,8 @@ app.post("/from-url", zValidator("json", fromUrlSchema), async (c) => {
 	const { url } = c.req.valid("json");
 	try {
 		const result = await fetchImageFromUrl(url);
-		return c.json(result, 201);
+		const presignedUrl = await getImageUrl(result.filename);
+		return c.json({ ...result, presignedUrl }, 201);
 	} catch (err) {
 		const message = (err as Error).message;
 		// Known validation errors from the service