epic: break #84 (agentskit flow) into sub-issues

[EmersonBraun]

Story #84 (agentskit flow — visual YAML editor compiling to a durable DAG) is one bullet in the roadmap PRD. Split into:

• spec: YAML schema + DAG semantics
• compiler: YAML → executable graph
• web editor (visual)
• runtime DAG executor on top of @agentskit/runtime
• durability layer (Temporal-style snapshot/resume)
• example: 3-node real flow shipped end-to-end

Currently too big to grab. As an epic, this unblocks the no-code campaign builder and the live multi-agent topology graph.

Acceptance

• Six sub-issues filed and linked back here
• Each sub-issue is independently grabbable

[EmersonBraun]

This is a meta / planning issue (RFC, plan refresh, release-timing decision) that needs maintainer judgement and stakeholder input rather than code changes. Leaving open.