disk-load retires the readings of a module whose key went while its watch was down (review round 2)

A key deleted while disk-load was not watching (a restart, a reboot, a machine asleep) never
arrives as a delete. Once the watch has handed over every current key, the readings of modules
with no key are retired once; an empty set is skipped and said, since the engine has not written.

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

modules/disk-load/cmd/disk-load/keeper.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/health"
 	"os"
 	"os/exec"
@@ -286,13 +287,47 @@ func (k *Keeper) MeasureModule(ctx context.Context, module string) {
 // asked only on a change of that module's key (novox/hq ADR 0577 clause 2), never from a round. It is cleared when the
 // item is declared again (measureOne).
 func (k *Keeper) retireGone(module string, declared []catalogue.PlacedDataItem) (int, error) {
+	return k.retire(func(r health.Reading) bool { return r.Module == module }, declared)
+}
+
+// RetireUnkeyed retires, once the watch handed over every current key, the readings of this node whose module has no
+// key in that set: a key deleted while the watch was not up (disk-load restarted, the machine rebooted or slept) never
+// reaches disk-load as a delete. An empty set is skipped and said: the engine has not written its keys yet, and an
+// empty set would retire every reading.
+func (k *Keeper) RetireUnkeyed(ctx context.Context) {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	items, err := k.Items(ctx)
+	if err != nil {
+		k.Say("the readings of modules with no key are not looked for: %v", err)
+		return
+	}
+	if len(items) == 0 {
+		k.Say("the node-engine's state %s holds no key of this machine yet: no reading is retired for it", delivery.EngineDataBucket)
+		return
+	}
+	var declared []catalogue.PlacedDataItem
+	for _, its := range items {
+		declared = append(declared, its...)
+	}
+	n, err := k.retire(func(r health.Reading) bool { _, keyed := items[r.Module]; return !keyed }, declared)
+	switch {
+	case err != nil:
+		k.Say("the readings of modules with no key are not all retired: %v", err)
+	case n > 0:
+		k.Say("%d reading(s) of modules with no key of this machine retired, measured no more", n)
+	}
+}
+
+// retire marks retired every reading of this node that of picks and declared does not name.
+func (k *Keeper) retire(of func(health.Reading) bool, declared []catalogue.PlacedDataItem) (int, error) {
 	keys, err := k.Store.Keys()
 	if err != nil {
 		return 0, err
 	}
 	declaredNow := map[string]bool{}
 	for _, it := range declared {
-		declaredNow[health.ReadingKey(k.Node, module, it.ID)] = true
+		declaredNow[health.ReadingKey(k.Node, it.Module, it.ID)] = true
 	}
 	now := k.Measurer.Now().UTC()
 	n := 0
@@ -305,7 +340,7 @@ func (k *Keeper) retireGone(module string, declared []catalogue.PlacedDataItem)
 			continue
 		}
 		r, err := health.DecodeReading(raw)
-		if err != nil || r.Node != k.Node || r.Module != module || !r.RetiredAt.IsZero() {
+		if err != nil || r.Node != k.Node || !of(r) || !r.RetiredAt.IsZero() {
 			continue
 		}
 		r.RetiredAt = now