Creates docs/swarm-memory-design.md — a comprehensive design note
that:
- Distinguishes session memory (private, ephemeral) from swarm memory
(shared, coordinated)
- Evaluates two candidate designs: append-only event log + synthesis
vs shared board + evidence links with CAS
- Documents trade-offs, failure modes, and proposed experimental
prototype using 3 concurrent subagents
- Sets acceptance baseline for issue #232
This is the smallest concrete step toward solving the swarm-memory gap:
a shared frame of reference that concurrent subagents can use to
coordinate without corrupting each other.
Closes#232
