Read the seat mesh-placement's state through the sdk's PlacementKeys in mesh-conditions, mesh-config, mesh-provisioner, mesh-vault and mesh-self-check, so they read its keys per module and node and the form before alike while it is delivered (issue 774, research 072 row 37)

modules/mesh-conditions/cmd/mesh-conditions/hold.go

@@ -216,26 +216,26 @@ func (k *Keeper) Have(key string, value []byte, deleted bool) error {
 	return k.judge(node, module, "")
 }
 
-// Placement takes one change of the placement: which module holds which seat on a node.
+// Placement takes one change of the placement: which module holds which seat on a node. The keys are read in either
+// form, a node key and its module keys or the form before (delivery.PlacementKeys; research 072 row 37).
 func (k *Keeper) Placement(key string, value []byte, deleted bool) {
-	node, err := delivery.ParsePlacementKey(key)
-	if err != nil {
-		return
-	}
 	k.mu.Lock()
 	defer k.mu.Unlock()
 	k.init()
+	node, err := k.placement.Put(key, value, 0, deleted)
+	if node == "" {
+		return
+	}
+	if err != nil {
+		k.Logf("the placement of %s is not readable as it stands, so its seats' holders are kept as last read: %v", node, err)
+	}
 	for hk := range k.holders {
 		if strings.HasPrefix(hk, node+".") {
 			delete(k.holders, hk)
 		}
 	}
-	if deleted {
-		return
-	}
-	p, err := delivery.DecodePlacement(value)
-	if err != nil {
-		k.Logf("the placement of %s is not readable, so its seats' holders are not known: %v", node, err)
+	p, _, ok := k.placement.Of(node)
+	if !ok {
 		return
 	}
 	for _, h := range p.Holds {

modules/mesh-conditions/cmd/mesh-conditions/hold_test.go

@@ -113,12 +113,19 @@ func TestADeliveryHoldsItsOwnFindingsUntilItEnds(t *testing.T) {
 	// A seat's finding is about the module the placement says holds the seat on that node (the lead, 2026-10-29): held
 	// while the assigner is delivered on ace, though the seat is named mesh-placement.
 	r := newRig()
-	placed, err := delivery.EncodePlacement(delivery.Placement{Node: "ace", Modules: []delivery.PlacedModule{{Module: "mesh-delivery-assigner"}},
+	// Research 072 row 37: the placement in its keys per module and node; a stale legacy key beside them is not read.
+	stale, err := delivery.EncodePlacement(delivery.Placement{Node: "ace"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	r.k.Placement("placement.ace", stale, false)
+	placed, err := delivery.PlacementValues(delivery.Placement{Node: "ace", Modules: []delivery.PlacedModule{{Module: "mesh-delivery-assigner"}},
 		Holds: []delivery.Holding{{Claim: "mesh-placement", Scope: "mesh", Module: "mesh-delivery-assigner"}}})
 	if err != nil {
 		t.Fatal(err)
 	}
-	r.k.Placement("placement.ace", placed, false)
+	r.k.Placement("ace.mesh-delivery-assigner", placed["ace.mesh-delivery-assigner"], false)
+	r.k.Placement("ace.node", placed["ace.node"], false)
 	_ = r.k.Want("want.ace.mesh-delivery-assigner", want(ctrlNext, ctrlNextComp), false)
 	_ = r.k.Have("ace.mesh-delivery-assigner", have(ctrlRunning, ctrlComposed, delivery.PhaseRunning, delivery.HealthOK), false)
 	seat, seatRaw := finding(t, selfCheck, health.ScopeSeat, "mesh-placement.ace", "holder-silent", "D3", health.Warning, r.now)

modules/mesh-conditions/cmd/mesh-conditions/keeper.go

@@ -112,8 +112,10 @@ type Keeper struct {
 	haves    map[string]delivery.Have
 	// holders are, by `<node>.<seat>`, the module the placement says holds the seat there.
 	holders map[string]string
-	stuck   map[string]string
-	held    map[string]held
+	// placement is the placement's keys as heard, assembled per node.
+	placement *delivery.PlacementKeys
+	stuck     map[string]string
+	held      map[string]held
 	// passed are the deliveries whose bound passed, by node and module, at the fingerprint wanted then; outOfHold the
 	// line a key raised out of a hold says (hold.go).
 	passed    map[string]string
@@ -130,6 +132,7 @@ func (k *Keeper) init() {
 			map[string]string{}, map[string]held{}, map[string]clearedMemo{}
 		k.takeover = health.Takeover{V: health.TakeoverVersion, Follow: health.FollowController}
 		k.passed, k.outOfHold, k.holders = map[string]string{}, map[string]string{}, map[string]string{}
+		k.placement = delivery.NewPlacementKeys()
 	}
 	if k.Now == nil {
 		k.Now = time.Now