ERC7579ModuleConfigStorage

struct ERC7579ModuleConfigStorage {
    /// @notice Installed modules per type: `_installed[moduleTypeId][module]`. APPEND-ONLY.
    mapping(uint256 moduleTypeId => mapping(address module => bool installed)) _installed;
    /// @notice The single global HOOK (type 4) wrapping the account's execution surface; 0 if none. APPEND-ONLY.
    address _hook;
    /// @notice FALLBACK (type 3) handlers per selector, consulted by `AccountDiamond` on a facet-map miss
    ///         (layered UNDER the facet map — `diamondCut` keeps selector authority). APPEND-ONLY.
    mapping(bytes4 selector => FallbackHandler) _fallbacks;
}