style: apply Biome formatting and auto-fixes

- Format 78 files, fixed 42 files total
- Apply safe lint fixes (non-null assertions converted to optional chaining)
- Remaining lint warnings are non-blocking (test code, a11y suggestions)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

packages/ui/vitest.config.ts

@@ -1,9 +1,9 @@
-import { defineConfig } from 'vitest/config';
+import { defineConfig } from "vitest/config";
 
 export default defineConfig({
-  test: {
-    globals: true,
-    environment: 'happy-dom',
-    setupFiles: ['./src/test-setup.ts'],
-  },
+	test: {
+		globals: true,
+		environment: "happy-dom",
+		setupFiles: ["./src/test-setup.ts"],
+	},
 });