Record that no API or flag exists only for custom CLIs, and Main tells one apart by its build info and file name

docs/decisions.md

@@ -148,7 +148,7 @@ A directory a machine happens to have would make `--seed 42` machine-dependent;
 - A manifest names no fejkdata version, and `New` checks none: the shipped packages ship in the core's Go module, and a module from anyone else keeps loading across a minor or a patch, as the README's Versioning promises. The maintainer chose so on 2026-10-09.
 - In the CLI, a flag of its own says a `--data-path` replaces what it clashes with, so flags still go anywhere on the line. Data authors and hand fixture authors bench it.
 - The README asks for functions with no side effects of their own.
-- The CLI is a library call. One exported list names every shipped package, and `fejkdata`'s own `main` passes it to that call. The list lives in a package of its own, so a library importing the core links no data it did not import. A custom CLI is the same few lines with other modules added, and no code exists only for custom CLIs. A README section shows it with example code, and the README's Library quick start shows the whole import block for one locale.
+- The CLI is a library call. One exported list names every shipped package, and `fejkdata`'s own `main` passes it to that call. The list lives in a package of its own, so a library importing the core links no data it did not import. A custom CLI is the same few lines with other modules added. No API and no flag exists only for custom CLIs; `Main` tells one apart only by its build info and file name, so its help and errors carry its name and its `--version` its own module's version beside fejkdata's. The maintainer chose so on 2026-10-11.
 - Before the module API ships, a panel of the README's audience personas tries pulling in data with it.
 
 Valid while the shipped data stays under 100 MiB, which a gate test holds (`todo.md` item 192): `go get` fetches the whole Go module, and the `go` command refuses a Go module zip over 500 MiB (`MaxZipFile` in `golang.org/x/mod/zip`). Past it, `todo.md` item 193 moves the largest packages into nested Go modules that keep their import paths, each requiring the core release that drops the package, so no build sees it twice.