Augment Intent adds coordinator, implementor, verifier agents

This is less about “more agents” and more about making the spec the control plane for agentic development.

• –The coordinator/implementor/verifier split mirrors a real engineering workflow: plan, execute, validate.
• –Editable agent behavior is the important part, because orchestration breaks fast when prompts stay rigid or drift from the codebase.
• –The living spec model is the real differentiator here; it reduces the usual chaos of multiple agents, stale prompts, and conflicting edits.
• –BYOA support makes Intent feel like a workflow layer, not just another model lock-in play.
• –The big question is whether the verifier is strong enough to catch meaningful issues before humans waste time reviewing noisy output.