chore: add svelte component layer with monaco editor

src/lib/themeIcons.ts

@@ -0,0 +1,93 @@
+export const THEME_ICON_SETS = [
+  {
+    value: 'lucide',
+    label: 'Lucide',
+    description: 'Clean geometric outlines. The launcher default.',
+  },
+  {
+    value: 'phosphor',
+    label: 'Phosphor',
+    description: 'Soft, rounded shapes with a friendly feel.',
+  },
+  {
+    value: 'tabler',
+    label: 'Tabler',
+    description: 'Crisp, technical outlines with a larger family.',
+  },
+] as const;
+
+export type ThemeIconSet = (typeof THEME_ICON_SETS)[number]['value'];
+
+export const DEFAULT_THEME_ICON_SET: ThemeIconSet = 'lucide';
+
+export const isThemeIconSet = (value: unknown): value is ThemeIconSet =>
+  THEME_ICON_SETS.some((set) => set.value === value);
+
+/**
+ * Semantic icon names used by launcher chrome. Themes choose a family, never a
+ * component import, so the launcher can swap families without changing layout.
+ */
+export const THEME_ICON_NAMES = [
+  'home',
+  'themes',
+  'settings',
+  'launch',
+  'user',
+  'music',
+  'brush',
+  'wifi',
+  'wifi-off',
+  'gameplay',
+  'integrations',
+  'installation',
+  'installed',
+  'diagnostics',
+  'logs',
+  'all-themes',
+  'available',
+  'updates',
+  'search',
+  'folder',
+  'plus',
+  'osu-standard',
+  'osu-taiko',
+  'osu-catch',
+  'osu-mania',
+  'login',
+  'logout',
+  'warning',
+  'info',
+  'loader',
+  'ellipsis',
+  'check',
+  'trash',
+  'edit',
+  'history',
+  'refresh',
+  'download',
+  'import',
+  'arrow-right',
+  'eye',
+  'eye-off',
+  'wrench',
+  'rotate',
+  'volume',
+  'volume-low',
+  'volume-off',
+] as const;
+
+export type ThemeIconName = (typeof THEME_ICON_NAMES)[number];
+
+const ICON_NAME_SET = new Set<string>(THEME_ICON_NAMES);
+
+export const isThemeIconName = (value: unknown): value is ThemeIconName =>
+  typeof value === 'string' && ICON_NAME_SET.has(value);
+
+/** A small representative row used by the editor's live icon preview. */
+export const THEME_ICON_PREVIEW_NAMES: ThemeIconName[] = [
+  'home',
+  'themes',
+  'settings',
+  'launch',
+  'user',
+];