"Talk is not cheap here. Talk is how the itinerary gets built — but only after you say yes."
A Turn Can Propose a Mutation
If conversation is planning, then a conversational turn has to be able to change the plan — otherwise it is just chatting. In Waystone, a single turn may produce one or more proposed domain mutations: add, remove, or reorder a day; add a candidate place or promote it to planned; compare routes or hotels; record a recommendation and its rationale; record Dad's decision; create a travel event; open a linked writing document. The conversation is not decoration on top of a form — it is the primary way structured state gets written.
Proposal, Then Accept — Never Silent
But here is the discipline that keeps it trustworthy: Pippa presents material changes as a visible proposal or diff, and Dad can accept, reject, or refine them in the same conversation. Nothing material is written the instant it is mentioned. Only acceptance turns a proposal into canonical Waystone state. This is a deliberate refusal of the "the AI just did it" pattern, where an assistant silently mutates your data and you discover the change later. In Waystone, the boundary between "Pippa suggested" and "this is now true" is an explicit, human act.
Accepted State Carries Provenance
When a proposal is accepted, the resulting state does not arrive as an orphan. It keeps provenance back to the conversation and the decision that produced it. Months later, you can look at a day that was added or a place that was promoted and trace why — which turn, which reasoning, which decision. That provenance is what turns a pile of itinerary edits into a defensible history. An edit you cannot explain is an edit you cannot trust; an edit with lineage is one you can audit, revisit, and learn from.