unused-assumptions: the published repository learns what to keep out

The unused-assumptions repository now separates what is published from what is merely being worked on: outreach/ workshop text for upstream pull requests and messages — including other people’s contact details and prose that is not its author’s to publish — is ignored at the root rather than parked in a sibling repository (43e092a), since the drafts are about this project’s results and belong beside them. The same instinct ran through the leak-detector test, which had been asserting that no shipped tool names the private sibling project while spelling out exactly those names as literals — now assembled from fragments so the repository stops carrying the one string it exists to withhold (3e1cb9a, 78ce2c0). One weakening was also withdrawn as unwanted despite compiling (b0e1f4f): a patch surviving the compiler is not the same as a patch worth publishing.