What makes a great Keel slice summary?

[rupurt]

In a good Keel session, a slice summary can tell you the whole move in one glance:

• board lineage
• authored artifacts
• what the slice captures
• current Keel status
• next explicit step

What else should a great slice summary include?

Possible additions:

• open risks
• missing proof
• unresolved design questions
• requirement coverage
• role/lane routing context
• recommended commit boundary

If we standardize this well, it could become one of the most useful public-facing Keel surfaces.