refactor(cli): move theme preset scripts into atbb CLI as theme subcommands
Moves `publish-presets.ts` and `bootstrap-local-presets.ts` from
`apps/appview/scripts/` into the `@atbb/cli` package as
`atbb theme publish-canonical` and `atbb theme bootstrap-local`.
Both commands sit alongside the existing init/category/board commands
and reuse the CLI's ForumAgent auth infrastructure. The appview npm
scripts that wrapped the old scripts are removed.