plan-change - drive the discussion that produces the ADR + spec

A piece of work worth doing usually has two documents worth writing before code:

• An ADR for the architectural choices the change requires (new table, new service boundary, new dependency, new transport, new pattern, or a non-trivial refactor of an existing one).
• A Gherkin spec for the behaviour - what the user does, what the system does back, what counts as success, what the edge cases are.

plan-change is the "I'm starting something" workhorse. It drives an interactive discussion to fill out both documents at the same time, then writes them cross-linked. It composes the same logic as /write-adr and /write-spec - you can use either of those standalone if you only need one half.

Usually /plan-change is reached via /start-feature (which sorts new vs existing first, and runs /backfill-feature if the feature has no ADR yet). Call it directly when you already know it's the right tool.