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/seed/skip-media-download.test.ts

@@ -0,0 +1,204 @@
+import type { Kysely } from "kysely";
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+
+import { ContentRepository } from "../../../src/database/repositories/content.js";
+import type { Database } from "../../../src/database/types.js";
+import type { MediaValue } from "../../../src/media/types.js";
+import { SchemaRegistry } from "../../../src/schema/registry.js";
+import { applySeed } from "../../../src/seed/apply.js";
+import type { SeedFile } from "../../../src/seed/types.js";
+import { setupTestDatabase, teardownTestDatabase } from "../../utils/test-db.js";
+
+// Mock fetch globally -- should NOT be called when skipMediaDownload is true
+const mockFetch = vi.fn();
+vi.stubGlobal("fetch", mockFetch);
+
+describe("applySeed with skipMediaDownload", () => {
+	let db: Kysely<Database>;
+
+	beforeEach(async () => {
+		db = await setupTestDatabase();
+		mockFetch.mockReset();
+
+		// Set up a collection with an image field
+		const registry = new SchemaRegistry(db);
+		await registry.createCollection({ slug: "posts", label: "Posts" });
+		await registry.createField("posts", {
+			slug: "title",
+			label: "Title",
+			type: "string",
+		});
+		await registry.createField("posts", {
+			slug: "featured_image",
+			label: "Featured Image",
+			type: "image",
+		});
+	});
+
+	afterEach(async () => {
+		await teardownTestDatabase(db);
+		vi.restoreAllMocks();
+	});
+
+	it("should resolve $media to external URL without downloading", async () => {
+		const seed: SeedFile = {
+			version: "1",
+			content: {
+				posts: [
+					{
+						id: "post-1",
+						slug: "hello",
+						data: {
+							title: "Hello World",
+							featured_image: {
+								$media: {
+									url: "https://images.unsplash.com/photo-abc123",
+									alt: "A test image",
+									filename: "test-image.jpg",
+								},
+							},
+						},
+					},
+				],
+			},
+		};
+
+		const result = await applySeed(db, seed, {
+			includeContent: true,
+			skipMediaDownload: true,
+		});
+
+		// Media should be "created" (resolved) but not downloaded
+		expect(result.media.created).toBe(1);
+		expect(result.content.created).toBe(1);
+
+		// fetch should NOT have been called
+		expect(mockFetch).not.toHaveBeenCalled();
+
+		// Check the content has an external MediaValue
+		const contentRepo = new ContentRepository(db);
+		const entry = await contentRepo.findBySlug("posts", "hello");
+		expect(entry).toBeDefined();
+
+		const image = entry!.data.featured_image as MediaValue;
+		expect(image).toBeDefined();
+		expect(image.provider).toBe("external");
+		expect(image.src).toBe("https://images.unsplash.com/photo-abc123");
+		expect(image.alt).toBe("A test image");
+		expect(image.filename).toBe("test-image.jpg");
+		expect(image.id).toBeDefined(); // synthetic ULID
+	});
+
+	it("should not require a storage adapter", async () => {
+		const seed: SeedFile = {
+			version: "1",
+			content: {
+				posts: [
+					{
+						id: "post-1",
+						slug: "no-storage",
+						data: {
+							title: "No Storage",
+							featured_image: {
+								$media: {
+									url: "https://example.com/image.jpg",
+									alt: "Test",
+								},
+							},
+						},
+					},
+				],
+			},
+		};
+
+		// No storage adapter provided -- should work fine with skipMediaDownload
+		const result = await applySeed(db, seed, {
+			includeContent: true,
+			skipMediaDownload: true,
+			// Intentionally no storage
+		});
+
+		expect(result.media.created).toBe(1);
+		expect(result.content.created).toBe(1);
+		expect(mockFetch).not.toHaveBeenCalled();
+	});
+
+	it("should cache external media references by URL", async () => {
+		const seed: SeedFile = {
+			version: "1",
+			content: {
+				posts: [
+					{
+						id: "post-1",
+						slug: "first",
+						data: {
+							title: "First Post",
+							featured_image: {
+								$media: {
+									url: "https://example.com/shared-image.jpg",
+									alt: "First alt",
+								},
+							},
+						},
+					},
+					{
+						id: "post-2",
+						slug: "second",
+						data: {
+							title: "Second Post",
+							featured_image: {
+								$media: {
+									url: "https://example.com/shared-image.jpg",
+									alt: "Second alt",
+								},
+							},
+						},
+					},
+				],
+			},
+		};
+
+		const result = await applySeed(db, seed, {
+			includeContent: true,
+			skipMediaDownload: true,
+		});
+
+		// First occurrence created, second from cache (skipped)
+		expect(result.media.created).toBe(1);
+		expect(result.media.skipped).toBe(1);
+		expect(result.content.created).toBe(2);
+
+		// Second entry should use the cached alt override
+		const contentRepo = new ContentRepository(db);
+		const second = await contentRepo.findBySlug("posts", "second");
+		const image = second!.data.featured_image as MediaValue;
+		expect(image.alt).toBe("Second alt");
+		expect(image.src).toBe("https://example.com/shared-image.jpg");
+	});
+
+	it("should handle content with no $media refs when skipMediaDownload is set", async () => {
+		const seed: SeedFile = {
+			version: "1",
+			content: {
+				posts: [
+					{
+						id: "post-1",
+						slug: "no-media",
+						data: {
+							title: "No Media",
+						},
+					},
+				],
+			},
+		};
+
+		const result = await applySeed(db, seed, {
+			includeContent: true,
+			skipMediaDownload: true,
+		});
+
+		expect(result.content.created).toBe(1);
+		expect(result.media.created).toBe(0);
+		expect(mockFetch).not.toHaveBeenCalled();
+	});
+});