Build briefs

A brief is one pair: a topic that is rising in our index, and a systems language (Rust, Go, Zig) that no repository in that topic is written in. Everything on a brief page is a template filled with numbers counted from our own tables, so every sentence can be checked against a query. A brief is not a recommendation and not a model output: it states what we measured, who already tried, what those projects look like today, the first milestone we can measure, and the date the brief becomes a miss. Publishing a brief here starts a 90-day window, and when a repository appears in our index in that topic and language afterwards we tag it. That tag is a topic and language match, never a claim that the brief caused the repository to exist.