feat(bonfire): global flags, Artisan list and exit codes

- Global options -v/-vv/-vvv, -q, --ansi/--no-ansi, -n and --env on every
  command; PeekGlobals reads them before config loads, OnGlobals hooks
  re-apply them after parsing (diary.ApplyGlobals in the generated main)
- Bare binary, --help and list print the Artisan list with the version
  header from BuildVersion and namespace blocks
- Execute runs the root through fang (no version, man page or completions)
  and returns 0, 1 or 2; Fail renders errors before the root exists
- NewRoot rejects duplicate command names (ErrDuplicateCommand) and flags
  that reuse a global option (ErrReservedFlag)
- Generated main and summer use PeekGlobals, compass.Open with --env,
  diary.FromGlobals and bonfire.Execute; docs checker knows the globals

cmd/summer/docs.go

@@ -136,13 +136,15 @@ func docsOptions(in bonfire.Input) docsite.Options {
 }
 
 // docsCommands collects the command names docs pages may show: the summer
-// tool's own commands, and every command the generated application main
+// tool's own commands, list and help (added by bonfire.NewRoot), and every
+// command the generated application main
 // registers (TestDocsCommandsMirrorGeneratedMain keeps this list in step
 // with internal/build) plus the realtime and push commands applications
 // append. The constructors only capture the app, so an empty config is
 // enough; nothing runs.
 func docsCommands() *docsite.Commands {
-	var tool []string
+	// list and help come from bonfire.NewRoot, in both programs.
+	tool := []string{"list", "help"}
 	for _, c := range toolCommands() {
 		tool = append(tool, c.Name)
 	}
@@ -156,7 +158,7 @@ func docsCommands() *docsite.Commands {
 	appCmds = append(appCmds, cabana.RuntimeCommands(app)...)
 	appCmds = append(appCmds, centrifugo.Commands(app)...)
 	appCmds = append(appCmds, flare.Commands(app)...)
-	names := make([]string, 0, len(appCmds))
+	names := []string{"list", "help"}
 	for _, c := range appCmds {
 		names = append(names, c.Name)
 	}