Add OrgAvatar component and frontend-utils package

- Create @reviq/frontend-utils package for frontend-specific utilities
- Add OrgAvatar component with size variants (xs, sm, md, lg, xl)
- Display org initials with deterministic colors when no logo available
- Add getOrgInitials and getOrgColor utility functions
- Update org-switcher and all org display pages to use OrgAvatar
- Add noNonNullAssertion lint rule as error in biome.jsonc

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/frontend-utils/eslint.config.js

@@ -0,0 +1,15 @@
+import { configs } from "@macalinao/eslint-config";
+
+export default [
+  ...configs.fast,
+  {
+    ignores: ["**/*.test.ts"],
+  },
+  {
+    languageOptions: {
+      parserOptions: {
+        tsconfigRootDir: import.meta.dirname,
+      },
+    },
+  },
+];