Uniswap V2 security incidents

Add PoC: KolanHook Uniswap v4 hook spot-price manipulation drain (1.2…

A Proof of Concept (PoC) has been added detailing a spot-price manipulation drain on a KolanHook Uniswap v4 hook, resulting in a loss of 1.279453 ETH on the Ethereum network. The exploit involved flash-borrowing WETH, manipulating the KLN spot price, and then using expired windows to misposition escrowed ETH as liquidity for an unbounded buyback.