chore: Zod v4 email, ESLint 10, and SPA deep-link routing

Migrate deprecated z.string().email() to z.email(), upgrade ESLint and
react-hooks with lint fixes, and route only /api/* through the Worker so
SPA deep links resolve correctly in production.

Author: claudio-silva

eslint.config.js

@@ -5,7 +5,7 @@ import reactRefresh from "eslint-plugin-react-refresh";
 import tseslint from "typescript-eslint";
 
 export default tseslint.config(
-  { ignores: ["dist"] },
+  { ignores: ["dist", "worker-configuration.d.ts"] },
   {
     extends: [js.configs.recommended, ...tseslint.configs.recommended],
     files: ["**/*.{ts,tsx}"],