Add whitespace validation to arcade server game ID validation

[Copilot]

The validateGameId function was missing whitespace validation, allowing game IDs with spaces, tabs, or newlines to pass validation. This could lead to URL construction issues and potential injection vectors.

Changes:

• Added regex check !/\s/.test(gameId) to reject any whitespace characters in game identifiers

function validateGameId(gameId: string): boolean {
  return (
    gameId.length > 0 &&
    !gameId.includes("/") &&
    !gameId.includes("?") &&
    !gameId.includes("#") &&
    !gameId.includes("..") &&
    !/\s/.test(gameId)  // Reject whitespace (spaces, tabs, newlines, etc.)
  );
}

Archive.org identifiers should not contain whitespace; this validation ensures malformed IDs are rejected before URL construction.

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[Copilot]

Pull request overview

This PR enhances the security of the arcade server by adding whitespace validation to game identifier validation. The change prevents malformed archive.org identifiers containing spaces, tabs, or newlines from being processed, which could lead to URL construction issues.

Changes:

• Added regex check !/\s/.test(gameId) to reject whitespace characters in the validateGameId function

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