`run_campaign_returning` runs the resolve->execute body and returns a
`CampaignRun` bundle (outcome + campaign/strategies/server); `present_campaign`
consumes it for the stdout tail; `run_campaign_by_id` becomes their composition.
Behaviour-preserving — the existing campaign + sweep-sugar e2e stay green
(research_docs 54/0 incl. the real-data e2e, sweep dissolution e2e green).
Exposes the outcome so the forthcoming generalize sugar can read it without the
presentation tail.
refs #210
Brummel
9ddea840dd