docs(adr): 0047 a break waits for a minor release that a feature brings

[ShortArrow]

ADR 0047 §2 said only that a break of the --json or config.toml contract needs a minor version. It did not say when a minor version is cut, or whether a change in what a setting does counts as a break. The timeout_ms change (#250) fell into that gap. It made unchanged configurations stop slow measurements, and it was prepared as 0.4.1 (#288) before it was moved into 0.5.0 (#291).

§2 now says three things.

• The config.toml contract covers what a value does as well as how it is spelled. Under that reading, timeout_ms broke it.
• A minor version is cut for a feature large enough to carry one, and the breaks that are waiting ride along with it. A break alone does not move the minor version, so breaks are released together, not one minor version each.
• While a break waits on main, main cuts no patch release. A fix owed to the current minor line ships from a maintenance branch under ADR 0022's existing rule.

The last point follows from the first two. Without it, a patch cut from main would carry the waiting break, which §2 already forbids.