The community treasury is envisioned to be a project where the community can apply for funding and the community can also decide if they want to approve the funding.
First there will be an initial voting on if the community wants to have a community treasury or if they want to burn the unclaimed tokens. You can read more about the unclaimed tokens in this blog post from the IF.
The initial voting will work with the tools currently available on mainnet. So it will "just" be a plugin that node operators can run to count votes and people can vote for BUILD or BURN in Firefly. You can read more about this topic here.
If the community votes for BUILD a DAO(decentralized autonomous organization) will be build. The DAO will use available IOTA tools like ISCP and identity to be the fairest and best solution possible.