Get the current APY for a specific Morpho vault by its contract address. Returns gross APY, net APY (after fees), TVL, and underlying asset info. Unlike 'Morpho Get Best APY' which discovers the highest-yielding vault for a token, this action looks up a known vault directly — use it when you already know which vault to check (e.g., after a deposit or withdrawal). Supports Ethereum (1), Optimism (10), Polygon (137), Base (8453), Arbitrum (42161). Ideal for: post-deposit APY reporting, vault monitoring, Slack/Telegram notifications with accurate yield data.