chore: update dependencies and fix Node.js 25 compatibility

- Update 15+ dependencies to latest versions
- Fix: replace deprecated fs.rmdir() with fs.rm() for Node.js 25+ compatibility
  - Breaking change from @types/node@24.10.1 → 25.0.3
  - Update cleanupTempDir() to use fs.rm({ recursive, force })
- Disable security/detect-non-literal-fs-filename for scripts (test utilities)
- Add ESLint disable comment for TOC heading (UI label, not content)

Key dependency updates:
- @types/node: 24.10.1 → 25.0.3 (breaking change)
- react/react-dom: 19.2.0 → 19.2.3
- vitest: 4.0.10 → 4.0.16
- @vitest/*: 4.0.10 → 4.0.16
- openai: 6.9.0 → 6.15.0
- zod: 4.1.12 → 4.2.1
- lefthook: 2.0.4 → 2.0.13

All 1537 tests passing. TypeScript and ESLint clean.

Author: luandro

eslint.config.mjs

@@ -90,6 +90,8 @@ export default [
       ...importPlugin.configs.recommended.rules,
       ...promisePlugin.configs.recommended.rules,
       ...securityPlugin.configs.recommended.rules,
+      // Test utilities intentionally use dynamic file paths
+      "security/detect-non-literal-fs-filename": "off",
     },
   },
 ];