MechMarketplace protocol fee activation. This proposal switches the universal MechMarketplace fee from 0 to 15% (newFee = 1500, MAX_FEE_FACTOR = 10000) on every MechMarketplaceProxy deployment across the supported EVM mainnets, by calling changeMarketplaceParams(1500, 60, 300) on each instance. Mode is excluded as no MechMarketplace is deployed on Mode. Ethereum is updated directly; Gnosis, Polygon, Arbitrum, Optimism, Base and Celo are updated through their respective L1->L2 bridge mediators (AMB, FxRoot, Arbitrum Inbox, and the OP-stack L1CrossDomainMessenger for Optimism/Base/Celo). The minResponseTimeout (60s) and maxResponseTimeout (300s) values are echoed unchanged. In accordance with Autonolas DAO Constitution at ipfs://bafybeibrhz6hnxsxcbv7dkzerq4chssotexb276pidzwclbytzj7m4t47u