Fix flatted security vulnerabilities

[michalv8]

Summary

• Override flatted to >=3.4.2 to fix two high-severity vulnerabilities:
  • Bump @types/eslint from 8.56.4 to 8.56.9 #27: Unbounded recursion DoS in parse()
  • Bump @typescript-eslint/parser from 7.1.0 to 7.6.0 #28: Prototype Pollution via parse()
• Follows existing override pattern for braces, cross-spawn, and rollup

Test plan

• npm ls flatted confirms version 3.4.2
• npm test passes (all 10 tests)

🤖 Generated with Claude Code