akm 0.7.0: Proposal Queue, Reflection Commands, Lessons, and akm-bench

akm 0.7.0 is out. This is the last pre-1.0 ship in the v1 cycle. The headline features are a durable proposal queue that routes all agent-suggested changes through a single reviewable path, three new CLI surfaces (reflect, propose, distill) that write into that queue, a lesson asset type for synthes