feat(lathe): add generated CLI self update

docs/cli-usage.md

@@ -88,6 +88,27 @@ set it to `""` to disable Skill generation. The optional `skill.include` value
 points at repo-local Skill resources merged into generated Skill files. Keep the
 include directory outside `skill.root`.
 
+Generated CLIs expose `--version` and `-v`. The release version is
+build metadata, not `cli.yaml` data: pass `Version`, `Commit`, and `Date` through
+`lathe.RunOptions`, or inject `github.com/lathe-cli/lathe/pkg/lathe.Version`,
+`Commit`, and `Date` with Go `-ldflags` in your release build.
+
+To let the generated CLI update itself from GitHub Releases, add:
+
+```yaml
+update:
+  github:
+    owner: acme
+    repo: acmectl
+    asset: "acmectl_{{ .Version }}_{{ .OS }}_{{ .Arch }}.tar.gz"
+```
+
+`asset` is a Go template with `Name`, `Version`, `Tag`, `OS`, and `Arch`.
+`update` fetches the latest GitHub release, reports when the current binary is
+already current, and asks for confirmation before replacing the executable. Pass
+`--yes` to skip the prompt. The release asset must expose a `sha256:` digest; zip,
+tar.gz, and tgz assets must contain a binary named after `cli.name`.
+
 ## Declare API Specs
 
 Create `specs/sources.yaml`:

internal/codegen/render/render.go

@@ -125,6 +125,7 @@ var reservedRootCommands = map[string]bool{
 	"commands": true,
 	"help":     true,
 	"search":   true,
+	"update":   true,
 }
 
 func MergeOverlay(specs []runtime.CommandSpec, overrides map[string]overlay.Override) []runtime.CommandSpec {

internal/codegen/render/skill.go

@@ -261,6 +261,12 @@ func renderSkillMD(manifest *config.Manifest, refs []moduleRef) string {
 	fmt.Fprintf(&b, "- `%s commands show <path...> --json`: source of truth for one command.\n", cli)
 	fmt.Fprintf(&b, "- `%s commands schema --json`: catalog schema version for parser compatibility.\n", cli)
 	fmt.Fprintf(&b, "- `%s search \"<intent>\" --json`: ranked candidate commands.\n\n", cli)
+	b.WriteString("## Maintenance Commands\n\n")
+	fmt.Fprintf(&b, "- `%s --version` or `%s -v`: print CLI build version.\n", cli, cli)
+	if manifest.Update.GitHub != nil {
+		fmt.Fprintf(&b, "- `%s update`: update this CLI from configured GitHub Releases. Run only when the user explicitly asks to update `%s`; it may replace the current executable. Use `--yes` only when explicitly authorized.\n", cli, cli)
+	}
+	b.WriteString("\n")
 	b.WriteString("## References\n\n")
 	b.WriteString("- Read `references/catalog.md` for the command discovery protocol and catalog field meanings.\n")
 	for _, ref := range refs {

pkg/config/manifest.go

@@ -9,8 +9,9 @@ import (
 )
 
 type Manifest struct {
-	CLI  CLIInfo  `yaml:"cli"`
-	Auth AuthInfo `yaml:"auth"`
+	CLI    CLIInfo    `yaml:"cli"`
+	Auth   AuthInfo   `yaml:"auth"`
+	Update UpdateInfo `yaml:"update,omitempty"`
 }
 
 type CLIInfo struct {
@@ -26,6 +27,16 @@ type AuthInfo struct {
 	Validate *AuthValidate `yaml:"validate,omitempty"`
 }
 
+type UpdateInfo struct {
+	GitHub *GitHubUpdate `yaml:"github,omitempty"`
+}
+
+type GitHubUpdate struct {
+	Owner string `yaml:"owner"`
+	Repo  string `yaml:"repo"`
+	Asset string `yaml:"asset"`
+}
+
 type AuthValidate struct {
 	Method  string              `yaml:"method"`
 	Path    string              `yaml:"path"`
@@ -59,6 +70,14 @@ func Load(bytes []byte) (*Manifest, error) {
 	if m.CLI.Name == "" {
 		return nil, fmt.Errorf("cli.name is required")
 	}
+	if m.Update.GitHub != nil {
+		m.Update.GitHub.Owner = strings.TrimSpace(m.Update.GitHub.Owner)
+		m.Update.GitHub.Repo = strings.TrimSpace(m.Update.GitHub.Repo)
+		m.Update.GitHub.Asset = strings.TrimSpace(m.Update.GitHub.Asset)
+		if m.Update.GitHub.Owner == "" || m.Update.GitHub.Repo == "" || m.Update.GitHub.Asset == "" {
+			return nil, fmt.Errorf("update.github.owner, update.github.repo, and update.github.asset are required")
+		}
+	}
 	m.CLI.CommandPath = strings.ToLower(strings.TrimSpace(m.CLI.CommandPath))
 	if m.CLI.CommandPath == "" {
 		m.CLI.CommandPath = CommandPathAuto

pkg/lathe/lathe.go

@@ -28,9 +28,11 @@ func NewApp(m *config.Manifest) *cobra.Command {
 		Use:          m.CLI.Name,
 		Short:        m.CLI.Short,
 		Long:         agentHint(m.CLI.Name, m.CLI.Short),
+		Version:      versionInfo(),
 		SilenceUsage: true,
 	}
 	cmd.CompletionOptions.DisableDefaultCmd = true
+	cmd.SetVersionTemplate("{{.Use}} {{.Version}}\n")
 	cmd.PersistentFlags().String("hostname", "", fmt.Sprintf("Server hostname (overrides $%s)", m.CLI.HostEnv))
 	cmd.PersistentFlags().StringP("output", "o", "table", "Output format: table|json|yaml|raw")
 	cmd.PersistentFlags().Bool("insecure", false, "Skip TLS certificate verification for this invocation")
@@ -48,6 +50,9 @@ func NewApp(m *config.Manifest) *cobra.Command {
 	cmd.AddCommand(authCmd)
 	cmd.AddCommand(commandsCmd(m))
 	cmd.AddCommand(searchCmd(m))
+	if m.Update.GitHub != nil {
+		cmd.AddCommand(updateCmd(m))
+	}
 	cmd.AddCommand(metaCmd(m.CLI.Name))
 	return cmd
 }