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/src/components/SaveButton.tsx

@@ -0,0 +1,47 @@
+/**
+ * Save Button with inline feedback
+ *
+ * Shows state based on whether there are unsaved changes:
+ * - "Saved" when clean (no unsaved changes)
+ * - "Save" when dirty (has unsaved changes)
+ * - "Saving..." while saving
+ */
+
+import { Button, Loader } from "@cloudflare/kumo";
+import { useLingui } from "@lingui/react/macro";
+import { FloppyDisk, Check } from "@phosphor-icons/react";
+import type { ComponentProps } from "react";
+import * as React from "react";
+
+import { cn } from "../lib/utils";
+
+export interface SaveButtonProps extends Omit<ComponentProps<typeof Button>, "children" | "shape"> {
+	/** Whether there are unsaved changes */
+	isDirty: boolean;
+	/** Whether currently saving */
+	isSaving: boolean;
+}
+
+/**
+ * Button that reflects save state
+ */
+export function SaveButton({ isDirty, isSaving, className, disabled, ...props }: SaveButtonProps) {
+	const { t } = useLingui();
+	const isSaved = !isDirty && !isSaving;
+
+	return (
+		<Button
+			className={cn("min-w-[100px] transition-all", className)}
+			disabled={disabled || isSaving || isSaved}
+			variant={isSaved ? "secondary" : "primary"}
+			icon={isSaving ? <Loader size="sm" /> : isSaved ? <Check /> : <FloppyDisk />}
+			aria-live="polite"
+			aria-busy={isSaving}
+			{...props}
+		>
+			{isSaving ? t`Saving...` : isSaved ? t`Saved` : t`Save`}
+		</Button>
+	);
+}
+
+export default SaveButton;