v0.15.34 — task set-body

5dive task set-body <id|DIVE-N> <text...> [--append] — edit a task body after filing (DIVE-1920).

--body was add-time only; the only remaining route to fix or extend a body afterward was a direct sqlite UPDATE on the shared tasks.db, which a scoped-sudo maker can't do and an admin correctly declines to do unilaterally. It cost us three tickets in one night, each time pushing information somewhere less durable than the task it belonged to.

• Default OVERWRITES the whole body; --append tacks text on with a blank-line separator, since an addendum shouldn't clobber someone else's context.
• Works on recurring TEMPLATES — a template filed with an empty body otherwise carries its instructions only in whoever remembers them.
• Refused on a closed (done/cancelled) task; the remedy is task reject to reopen first.
• Audited with actor, mode (replaced/appended) and prior_len, which is what makes a destructive overwrite distinguishable from an append after the fact.

Built by dev2, reviewed and landed by main (PR #194).