"A successful draft stays addressable; a later failed attempt cannot erase or hide the last good result."
The Invariant That Makes Regeneration Safe
Last lesson said drafts are regenerable, disposable, and pluralizable — which sounds carefree until you notice the trap. If 'regenerate' meant 'overwrite in place', then one bad regeneration would destroy a draft you loved. You'd hesitate to ever hit the button again, and the freedom would be a lie. Vesta closes that trap with an inherited invariant: a successful draft remains independently addressable, and a later failed or worse attempt cannot erase or hide the last good result. Regeneration is safe precisely because a new attempt can never overwrite a good old one.
Mechanically, a draft carries a status — proposed, accepted, superseded — and a new assembly produces a new draft rather than mutating the existing one. Your accepted draft stays accepted and addressable until you explicitly choose to supersede it with something you like better. A regeneration that comes back weak, or an assembly that fails outright, simply doesn't become the accepted draft. The good result sits untouched, exactly where it was.
Bulk Generation Never Auto-Accepts
The same principle scales up. You might one day ask Pippa to assemble a whole month at once, or a year in review. That bulk generation may read many per-day proposals — but it never auto-accepts them on your behalf. An aggregate draft can consume grounded per-scope proposals as input, yet the review status stays explicit: you still decide what becomes accepted. A system that auto-accepted bulk output would be back to silently rewriting history at scale, and worse, it could bury good accepted drafts under machine-generated ones nobody reviewed.
Why This Is Inherited, Not Invented
Vesta didn't design this rule from scratch either — it's the shape of Waystone's own invariant that a successful result stays addressable and a later failed attempt can't erase it. Like the two-truth rule, it's scar tissue handed down: the parent learned that letting a retry clobber a good result loses work, wrote the invariant, and the child inherits the safety for free. Every 'regenerate' you trigger in Vesta is safe because a sibling already learned what happens when it isn't.