internal/rosa: optionally block packages from early stages

This helps avoid inadvertently increasing bootstrap input count.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/state.go

@@ -998,6 +998,8 @@ func (ctx *evalContext) pf(
 		overlay string
 
 		inputs, runtimes, extra azalea.Array
+
+		bootstrap = true
 	)
 	if err = args.Apply(map[unique.Handle[azalea.Ident]]any{
 		k("description"): &meta.Description,
@@ -1020,6 +1022,7 @@ func (ctx *evalContext) pf(
 		k("exclusive"):      &attr.Exclusive,
 		k("toyboxEarly"):    &attr.Early,
 		k("minimal"):        &attr.NoToolchain,
+		k("bootstrap"):      &bootstrap,
 
 		k("checksum"): &kc,
 		k("output"):   &output,
@@ -1032,6 +1035,7 @@ func (ctx *evalContext) pf(
 	}); err != nil {
 		return
 	}
+	attr.Std = !bootstrap
 	var inputsH, extraH P
 	if inputsH, err = toHandles(inputs); err != nil {
 		return