Make avatar imager resilient with upstream fallback everywhere

src/lib/imager.ts

@@ -6,8 +6,24 @@
 
 export type { AvatarOptions } from "@/types/admin";
 
+import type { SyntheticEvent } from "react";
 import type { AvatarOptions } from "@/types/admin";
 
+/**
+ * Neutral silhouette (grayscale SVG) shown when even the fallback upstream
+ * cannot produce a render — keeps a broken avatar from showing a broken-image
+ * glyph anywhere on the site.
+ */
+export const AVATAR_FALLBACK_SRC =
+	"data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 64 64'%3E%3Crect width='64' height='64' fill='%23e2e2e2'/%3E%3Ccircle cx='32' cy='24' r='11' fill='%239d9d9d'/%3E%3Cpath d='M10 60c5-10 13-14 22-14s17 4 22 14z' fill='%239d9d9d'/%3E%3C/svg%3E";
+
+export function avatarImageOnError(event: SyntheticEvent<HTMLImageElement>) {
+	const img = event.currentTarget;
+	if (img.dataset.fallback) return;
+	img.dataset.fallback = "1";
+	img.src = AVATAR_FALLBACK_SRC;
+}
+
 /**
  * Build an avatar image URL using the configured imager.
  * Uses effect=14 and img_format=apng by default for epicnabbo.nl compatibility.