Let each install pick its app icon

Settings > General gets an App icon (super admin): one of the seven
stones, or an uploaded image with the picked stone as a top-left corner
mark (inside a round launcher's crop, clear of the browser's badge),
previewed in both launcher crops before saving.

Uploads are decoded and cropped to a stored square (no SVG); the set is
drawn into DATA_DIR/install-icon/<version>/ and served publicly and
immutable. The manifest, head icon links and push notifications point at
it; the ember stone keeps the stock icons. The generator shares the icon
renderer.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/utils/parse-install-icon.ts

@@ -0,0 +1,40 @@
+import { BotHues, type BotHue } from "@/src/dict/bot-dict";
+import {
+    PwaDefaultInstallIcon,
+    PwaInstallIconModes,
+    type PwaInstallIcon,
+} from "@/src/data/pwa-data";
+
+type Params = {
+    /**
+     * The `install_icon` app setting, as saved.
+     */
+    saved?: string | null;
+};
+
+/**
+ * The install's icon from its saved JSON, field by field: anything missing
+ * or unknown falls back to the stock ember icon's value.
+ */
+export default function parseInstallIcon({ saved }: Params): PwaInstallIcon {
+    let raw: Record<string, unknown> = {};
+
+    try {
+        const parsed = saved ? JSON.parse(saved) : null;
+        if (parsed && typeof parsed == "object") raw = parsed;
+    } catch {
+        raw = {};
+    }
+
+    const mode = PwaInstallIconModes.find((value) => value == raw.mode);
+    const stone = BotHues.find((hue) => hue.value == raw.stone)?.value as BotHue | undefined;
+    const version =
+        typeof raw.version == "string" && /^[a-f0-9]{12}$/.test(raw.version) ? raw.version : null;
+
+    return {
+        mode: mode || PwaDefaultInstallIcon.mode,
+        stone: stone || PwaDefaultInstallIcon.stone,
+        mark: typeof raw.mark == "boolean" ? raw.mark : PwaDefaultInstallIcon.mark,
+        version,
+    };
+}