save-session — tactical checkpoint

Self-validate after edits. Any change to this skill's files (SKILL.md, scripts/, references/, templates/, assets/) must be followed by ./scripts/validate.sh from the skill directory. Hard findings → create-skill Optimize lane.

This skill exists to preserve the transient context that durable docs usually omit: what the operator was actively doing, what should happen first next time, what was already verified, and which small set of local files or commits matter at handoff.

When the session exposed preventable friction, use session-introspection before writing the checkpoint. Save the highest-value prevention control in the checkpoint so the next agent can continue from the control decision instead of rediscovering the same inefficiency.

Operating contract