Massachusetts legislators are debating the future of Gov. Charlie Baker’s $918 million economic development proposal, including investments in local infrastructure, emerging technologies, community-based innovation, brownfields cleanup, Gateway Cities development and workforce development. The proposal would implement several of the action items from Baker’s economic strategic plan, issued last November, over the next five years. About half of the funds would support local infrastructure projects, but other investments would bolster the Massachusetts’ Manufacturing Innovation Institutes, university tech commercialization and innovative co-working spaces.