Potential fix for https://github.com/ArcavenAE/ThreeDoors/security/code-scanning/9

Add an explicit upper-bound guard in LevenshteinDistance before slice allocations so len(b)+1 cannot overflow and cannot trigger impractically large allocations. The safest no-dependency approach is to cap input lengths using math.MaxInt arithmetic and return a conservative distance when inputs exceed safe bounds.

Best single fix:

• Edit internal/core/duplicate_detector.go.
• Import math.
• In LevenshteinDistance, after empty-string checks and before make, add:
  • if len(b) > math.MaxInt-1 { return len(b) }
  • Optional symmetric safety for a to keep behavior robust in loops: if len(a) > math.MaxInt-1 { return len(a) }
    This preserves existing functionality for normal inputs while preventing overflow at the flagged allocation site(s).

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