disk-load measures the items the node-engine keeps for its node, and composes nothing (ADR 0577)

It watches its node's keys of mesh-host_data instead of composing every module's items from
about 370 resolved keys per round, so a round no longer takes 30 to 45 minutes across the tunnel
and a manifest its mesh-sdk cannot judge no longer silences it. A changed key measures its module
at once; each round writes how far it got to the per-node state rounds, said by disk_round.
Pins mesh-sdk feat/data-items.

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

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

@@ -2,9 +2,11 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"sort"
 	"strings"
+	"time"
 
 	stdio "git.novox.be/novox/mesh-sdk/go"
 	"git.novox.be/novox/mesh-sdk/go/health"
@@ -68,6 +70,42 @@ func ReadingTools(k *Keeper) []stdio.Tool {
 					"cap": "none declared: the bus's own limit on a state applies"}}, nil
 			},
 		},
+		{
+			Name: "disk_round",
+			Description: "How far this machine's last round of measuring its data items got (novox/hq ADR 0577 clause 3), from " +
+				"disk-load's state `rounds`, key `<node>`: when it started and ended (no end while it runs), how many items it had, " +
+				"measured, wrote and kept unchanged, each item that failed and why, and how old the round is; `node` reads " +
+				"another machine's key. A round that never ends, or fails every item, shows here. (r)",
+			Input: map[string]any{
+				"node": map[string]any{"type": "string", "description": "the machine whose last round to read; this one by default"},
+			},
+			Run: func(args map[string]any) (any, error) {
+				node := text(args, "node")
+				if node == "" {
+					node = k.Node
+				}
+				if k.Rounds == nil {
+					return nil, fmt.Errorf("this disk-load keeps no rounds")
+				}
+				raw, err := k.Rounds.Get(node)
+				if err != nil {
+					return nil, err
+				}
+				if len(raw) == 0 {
+					return nil, fmt.Errorf("no round of %s is kept yet: its first round starts a few minutes after disk-load starts", node)
+				}
+				var r Round
+				if err := json.Unmarshal(raw, &r); err != nil {
+					return nil, fmt.Errorf("the round of %s is not readable: %w", node, err)
+				}
+				state := "ended"
+				if r.Ended == nil {
+					state = "running"
+				}
+				return map[string]any{"round": r, "state": state,
+					"age": k.Measurer.Now().UTC().Sub(r.Started).Round(time.Second).String()}, nil
+			},
+		},
 		{
 			Name: "disk_measure",
 			Description: "Measure one data item of this machine now, whatever its method (a walk too), and write its reading when it " +