feat(01-03): add deterministic rich CLI output

- Inject bonfire.Output from stdin/stdout/stderr with stdlib widgets and x/term
- Degrade spinner, progress, table and prompts without a TTY or color
- Reject plugin command names that are not namespace:verb

examples/hello/plugins/greeter/plugin.go

@@ -82,6 +82,10 @@ func (p *Plugin) Commands() []bonfire.Command {
 				}
 				handled = ok
 			}
+			out.Table([]string{"plugin", "status"}, [][]string{{"golem15.greeter", "active"}})
+			if _, err := out.Confirm("show greeting?", true); err != nil {
+				return err
+			}
 			out.Printf("name=%s posts_per_page=%d debug=%t extra=%s events=%s collected=%s handled=%t\n", name, posts, debug, p.extra, events, collected, handled)
 			return nil
 		},