Integrate selected builds with candidate workflows

docs/cli.md

@@ -1,6 +1,6 @@
 # Command line
 
-ReleaseKit currently provides three commands.
+ReleaseKit currently provides four commands.
 
 Print the executable version:
 
@@ -49,3 +49,26 @@ errors, and 3 when the push outcome remains unknown. Unknown status must be
 resolved against the authoritative remote before retrying. The
 [maintainer procedure](release.md) selects the repository profile and gives
 the source-release workflow.
+
+Build selected application targets:
+
+```sh
+go run ./cmd/releasekit build [--repo DIR] [--config FILE] [--output DIR] VERSION
+```
+
+`build` requires a `build` object in the profile. It compiles the selected
+targets with the requested version injected, checks the native `version`
+invocation, and writes binaries plus the private `.releasekit-build.json`
+receipt into `dist` by default. `--output` selects a different directory;
+relative paths are resolved from the repository. Existing files with a selected
+artifact name are preserved and cause an error. A complete nonempty build
+writes a receipt only after compilation and smoke checking succeed. On partial
+failure, standard error lists completed outputs and no receipt is written. An
+empty target list returns the source commit without building or writing a
+receipt.
+
+The command returns status 0 on completion, 1 for build or output failure, and
+2 for usage, profile, or invalid-version errors. It builds the current source
+tree and does not perform candidate validation or remote publication. `check`
+and `publish` run the same configured build after their one candidate
+validation, using temporary output outside the worktree.