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/webauthn-environment.test.ts

@@ -0,0 +1,54 @@
+import { describe, it, expect, afterEach } from "vitest";
+
+import {
+	isPasskeyEnvironmentUsable,
+	isPublicKeyCredentialConstructorAvailable,
+	isWebAuthnSecureContext,
+} from "../../src/lib/webauthn-environment";
+
+describe("webauthn-environment", () => {
+	const origPk = globalThis.window.PublicKeyCredential;
+	const desc = Object.getOwnPropertyDescriptor(globalThis.window, "isSecureContext");
+
+	afterEach(() => {
+		if (origPk === undefined) {
+			delete (globalThis.window as { PublicKeyCredential?: unknown }).PublicKeyCredential;
+		} else {
+			Object.defineProperty(globalThis.window, "PublicKeyCredential", {
+				value: origPk,
+				configurable: true,
+				writable: true,
+			});
+		}
+		if (desc) Object.defineProperty(globalThis.window, "isSecureContext", desc);
+	});
+
+	it("is usable only when secure context and PublicKeyCredential constructor exist", () => {
+		Object.defineProperty(globalThis.window, "isSecureContext", {
+			value: true,
+			configurable: true,
+		});
+		Object.defineProperty(globalThis.window, "PublicKeyCredential", {
+			value: function PublicKeyCredential() {},
+			configurable: true,
+			writable: true,
+		});
+		expect(isWebAuthnSecureContext()).toBe(true);
+		expect(isPublicKeyCredentialConstructorAvailable()).toBe(true);
+		expect(isPasskeyEnvironmentUsable()).toBe(true);
+	});
+
+	it("is not usable in an insecure context even if PublicKeyCredential is defined", () => {
+		Object.defineProperty(globalThis.window, "isSecureContext", {
+			value: false,
+			configurable: true,
+		});
+		Object.defineProperty(globalThis.window, "PublicKeyCredential", {
+			value: function PublicKeyCredential() {},
+			configurable: true,
+			writable: true,
+		});
+		expect(isWebAuthnSecureContext()).toBe(false);
+		expect(isPasskeyEnvironmentUsable()).toBe(false);
+	});
+});