Missing enforcement of Bridge::MAX_TOKEN_PAIRS

The Bridge.sol contract defines a MAX_TOKEN_PAIRS constant but does not enforce it when new token pairs are registered. In Bridge::registerKeyPairWithTransfer the code pushes tokens into the Bridge::supportedOriginalTokens array without checking length limits or duplicates. This allows unbounded growth of the array.

Enforce the MAX_TOKEN_PAIRS limit when registering new pairs:

require(
    supportedOriginalTokens.length < MAX_TOKEN_PAIRS,
    "max token pairs reached"
);

YadaCoin, Confirmed.

Zealynx, Fixed.