chore: enable plugin:react/recommended in ESLint config

[devin-ai-integration]

Summary

The current ESLint config (eslint.config.mjs) only enables react/jsx-no-target-blank. Consider enabling plugin:react/recommended for broader React lint coverage including rules like:

• react/jsx-key — enforce keys on iterators
• react/no-danger — flag dangerouslySetInnerHTML usage
• react/no-direct-mutation-state — prevent direct state mutation
• react/no-unescaped-entities — catch unescaped HTML entities in JSX

Context

Identified during PR #10 review. The minimal config was intentional for the initial ESLint setup to keep the diff small and focused.