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/admin/tests/components/RepeaterField.test.tsx

@@ -0,0 +1,45 @@
+import * as React from "react";
+import { describe, it, expect, vi } from "vitest";
+
+import { RepeaterField } from "../../src/components/RepeaterField";
+import { render } from "../utils/render.tsx";
+
+describe("RepeaterField", () => {
+	describe("datetime sub-field", () => {
+		it("displays a stored ISO datetime in the datetime-local input", async () => {
+			// Mirrors the top-level datetime widget contract: full ISO 8601
+			// values must round-trip through `<input type="datetime-local">`,
+			// which only accepts `YYYY-MM-DDTHH:mm`.
+			const screen = await render(
+				<RepeaterField
+					label="Recalls"
+					id="recalls"
+					value={[{ recall_date: "2026-02-26T09:30:00.000Z" }]}
+					onChange={vi.fn()}
+					subFields={[{ slug: "recall_date", type: "datetime", label: "Recall date" }]}
+				/>,
+			);
+			const input = screen.getByLabelText("Recall date");
+			await expect.element(input).toHaveValue("2026-02-26T09:30");
+		});
+
+		it("emits a full ISO 8601 value with Z and milliseconds on change", async () => {
+			const onChange = vi.fn();
+			const screen = await render(
+				<RepeaterField
+					label="Recalls"
+					id="recalls"
+					value={[{ recall_date: "" }]}
+					onChange={onChange}
+					subFields={[{ slug: "recall_date", type: "datetime", label: "Recall date" }]}
+				/>,
+			);
+			const input = screen.getByLabelText("Recall date");
+			await input.fill("2026-02-26T09:30");
+
+			expect(onChange).toHaveBeenLastCalledWith([
+				expect.objectContaining({ recall_date: "2026-02-26T09:30:00.000Z" }),
+			]);
+		});
+	});
+});