Emdash source with visual editor image upload fix

Fixes:
1. media.ts: wrap placeholder generation in try-catch
2. toolbar.ts: check r.ok, display error message in popover

packages/core/tests/unit/converters/image-missing-asset.test.ts

@@ -0,0 +1,92 @@
+import { describe, it, expect } from "vitest";
+
+import { portableTextToProsemirror } from "../../../src/content/converters/portable-text-to-prosemirror.js";
+import type { PortableTextBlock } from "../../../src/content/converters/types.js";
+
+describe("Image blocks without asset wrapper", () => {
+	it("does not crash when an image block has url at the top level instead of inside asset", () => {
+		// This is the format that can originate from migrations or third-party imports
+		// (e.g. Ghost → Portable Text). Without the fix, accessing block.asset.url
+		// throws TypeError: Cannot read properties of undefined (reading 'url').
+		const blocks: PortableTextBlock[] = [
+			{
+				_type: "block",
+				_key: "b1",
+				style: "normal",
+				children: [{ _type: "span", _key: "s1", text: "Before image", marks: [] }],
+				markDefs: [],
+			},
+			{
+				_type: "image",
+				_key: "img1",
+				url: "https://example.com/photo.jpg",
+				alt: "A photo without asset wrapper",
+			} as unknown as PortableTextBlock,
+			{
+				_type: "block",
+				_key: "b2",
+				style: "normal",
+				children: [{ _type: "span", _key: "s2", text: "After image", marks: [] }],
+				markDefs: [],
+			},
+		];
+
+		const result = portableTextToProsemirror(blocks);
+
+		expect(result.type).toBe("doc");
+		expect(result.content).toHaveLength(3);
+	});
+
+	it("extracts src and alt from top-level url when asset is missing", () => {
+		const blocks: PortableTextBlock[] = [
+			{
+				_type: "image",
+				_key: "img1",
+				url: "https://example.com/photo.jpg",
+				alt: "A test image",
+			} as unknown as PortableTextBlock,
+		];
+
+		const result = portableTextToProsemirror(blocks);
+		const imageNode = result.content[0];
+
+		expect(imageNode.type).toBe("image");
+		expect(imageNode.attrs?.src).toBe("https://example.com/photo.jpg");
+		expect(imageNode.attrs?.alt).toBe("A test image");
+	});
+
+	it("handles image block with neither asset nor url gracefully", () => {
+		const blocks: PortableTextBlock[] = [
+			{
+				_type: "image",
+				_key: "img1",
+			} as unknown as PortableTextBlock,
+		];
+
+		const result = portableTextToProsemirror(blocks);
+		const imageNode = result.content[0];
+
+		expect(imageNode.type).toBe("image");
+		expect(imageNode.attrs?.src).toBe("");
+		expect(imageNode.attrs?.alt).toBe("");
+	});
+
+	it("still converts well-formed image blocks with asset wrapper correctly", () => {
+		const blocks: PortableTextBlock[] = [
+			{
+				_type: "image",
+				_key: "img1",
+				asset: { _ref: "media-123", url: "https://example.com/photo.jpg" },
+				alt: "A proper image",
+			},
+		];
+
+		const result = portableTextToProsemirror(blocks);
+		const imageNode = result.content[0];
+
+		expect(imageNode.type).toBe("image");
+		expect(imageNode.attrs?.src).toBe("https://example.com/photo.jpg");
+		expect(imageNode.attrs?.alt).toBe("A proper image");
+		expect(imageNode.attrs?.mediaId).toBe("media-123");
+	});
+});