Passalong: handoffs for agent work

Field notes

Passalong packages technical context into guides containing the problem, decisions, steps, verification commands, and gotchas, then gives each published handoff a short ID and link. Its sample concerns a Postgres 16 order-total backfill: the page recommends primary-key batches of 5,000, checks `pg_stat_activity`, and describes a target of no lock waits over 50ms. Guides are described as Markdown with frontmatter and can be exported, while the hub and cross-machine sync require account access.