Keep a left-out module's provisions and backups, and refuse more identity keys (hq ADR 0262)

A module left out for an unknown key inside an entry lost its whole manifest, so every consumer of what
it provides was refused and its data stopped being copied. Read past only the unknown key, keep its
backup lines, and say in the condition what stops.

internal/catalogue/declaration.go

@@ -369,11 +369,16 @@ func (r Resolution) compose(with Rendering, owner map[string]string,
 	// Before placing, because a placement is a setting too.
 	left := r.LeftOut(with.Settings, with.Adopted)
 	kept := make([]Manifest, 0, len(r.Modules))
+	var stillBackedUp []Manifest
 	for _, m := range r.Modules {
 		if why, isLeft := left[m.Module]; isLeft {
 			if leftOut != nil {
 				leftOut[m.Module] = why
 			}
+			// **Its data is still copied** (novox/hq ADR 0262): a module left out runs nothing new, and
+			// the data it already holds on the machine is the reason to keep copying it. Only its data,
+			// as the backup holder's lines are derived from it, and the directories they name.
+			stillBackedUp = append(stillBackedUp, backupView(m))
 			continue
 		}
 		kept = append(kept, m)
@@ -979,7 +984,8 @@ func (r Resolution) compose(with Rendering, owner map[string]string,
 			// seat that places them (novox/hq ADR 0203, ADR 0204). Gathered from every module on
 			// the node, as the jails are, and **last of every placeholder pass**: shell code is a
 			// shell's own syntax, full of `${…}` no pass above should ever be shown.
-			if err := contributionsInto(copied, m, r.Modules, thisMachine, with, r.Capabilities, unplaced); err != nil {
+			contributing := append(append([]Manifest(nil), r.Modules...), stillBackedUp...)
+			if err := contributionsInto(copied, m, contributing, thisMachine, with, r.Capabilities, unplaced); err != nil {
 				return nil, err
 			}
 			copied["id"] = m.Module + "." + fmt.Sprint(resource["id"])