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/lib/datetime-local.test.ts

@@ -0,0 +1,42 @@
+import { describe, expect, it } from "vitest";
+
+import {
+	fromDatetimeLocalInputValue,
+	toDatetimeLocalInputValue,
+} from "../../src/lib/datetime-local";
+
+describe("toDatetimeLocalInputValue", () => {
+	it("returns empty for non-string and empty values", () => {
+		expect(toDatetimeLocalInputValue(undefined)).toBe("");
+		expect(toDatetimeLocalInputValue(null)).toBe("");
+		expect(toDatetimeLocalInputValue(0)).toBe("");
+		expect(toDatetimeLocalInputValue("")).toBe("");
+	});
+
+	it("strips seconds/ms/Z from full ISO 8601", () => {
+		expect(toDatetimeLocalInputValue("2026-02-26T09:30:00.000Z")).toBe("2026-02-26T09:30");
+	});
+
+	it("pads date-only values to UTC midnight", () => {
+		expect(toDatetimeLocalInputValue("2026-02-26")).toBe("2026-02-26T00:00");
+	});
+
+	it("preserves a value already in datetime-local shape", () => {
+		expect(toDatetimeLocalInputValue("2026-02-26T09:30")).toBe("2026-02-26T09:30");
+	});
+});
+
+describe("fromDatetimeLocalInputValue", () => {
+	it("returns empty for empty input", () => {
+		expect(fromDatetimeLocalInputValue("")).toBe("");
+	});
+
+	it("appends seconds/ms/Z so the value matches the validator's ISO shape", () => {
+		expect(fromDatetimeLocalInputValue("2026-02-26T09:30")).toBe("2026-02-26T09:30:00.000Z");
+	});
+
+	it("round-trips a stored ISO value without drift", () => {
+		const stored = "2026-02-26T09:30:00.000Z";
+		expect(fromDatetimeLocalInputValue(toDatetimeLocalInputValue(stored))).toBe(stored);
+	});
+});