feat(04-01): generate model, migration, and command artifacts

Add make:model, make:migration and make:command with plugin-id
inference, duplicate rejection, and a deterministic registry refresh
that leaves handwritten plugin.go untouched.

Co-authored-by: Cursor <cursoragent@cursor.com>

bonfire/command.go

@@ -26,6 +26,8 @@ type Flag struct {
 	Shorthand   string
 	Description string
 	Default     string
+	// Bare allows --flag without a value; cobra stores "true".
+	Bare bool
 }
 
 // Arg describes a positional argument.