W13.5: the node agent asks mesh-recovery for a restore point before a form change and restores it at a revert

Before a move across a kept data's form change the node agent asks snapshot-kept and waits for the ended of its own act; at a revert it stops the newer build (Env.Stop), asks kept-points, asks restore-kept with the snapshot of the point of the form and fingerprint it reverts from, waits for restored, applies the reverted build, and calls the point's catch-up as the module's tool through the tool runner. The wait is in the have (ask-at, act), bounded by a bounds key of the state bounds (recovery-wait-minutes, 90), and each ending is read as the table of 560 says. The manifest consumes mesh-recovery's ended and restored and invokes its three verbs.

Builds: design 47 G §296, §297, §554, §555, §560, §630, §631, §632, §633, A-77, A-92, A-98, A-108
Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h

internal/selfcompose/entries.go

@@ -15,6 +15,7 @@ import (
 	"git.novox.be/novox/mesh-delivery/contracts/go/seats/meshcatalog"
 	"git.novox.be/novox/mesh-delivery/contracts/go/seats/meshwants"
 	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-builder/builds"
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
 
 	"github.com/novox/mesh-host/internal/agent"
 )
@@ -514,3 +515,32 @@ func EntryCall(ask func(ctx context.Context, seat, verb string, args any) (json.
 
 // noEntryWords are the words the seat's holder refuses an unknown fingerprint in.
 const noEntryWords = "no entry of fingerprint"
+
+// FormChanges are the kept data whose form differs between the manifests of the build a module runs and the one a want moves it
+// to, each read from the entry the composer holds of its fingerprint (design 47 G §296, §297). An entry not held is an error: the
+// node agent then says it is not known and the move goes on.
+func (c *Composer) FormChanges(_ context.Context, module, runningFp, appliedFp string) ([]catalogue.FormChange, error) {
+	if !c.byEntries() {
+		return nil, fmt.Errorf("this engine reads no entry by fingerprint")
+	}
+	read := func(fp string) (catalogue.Manifest, error) {
+		e, state := c.entryOf(fp)
+		if state != meshcatalogclient.EntryAnswered {
+			return catalogue.Manifest{}, fmt.Errorf("the entry of %s is %s", fp, state)
+		}
+		_, raw, err := entryManifest(e)
+		if err != nil {
+			return catalogue.Manifest{}, err
+		}
+		return catalogue.Decode(raw)
+	}
+	running, err := read(runningFp)
+	if err != nil {
+		return nil, fmt.Errorf("%s's running manifest: %w", module, err)
+	}
+	applied, err := read(appliedFp)
+	if err != nil {
+		return nil, fmt.Errorf("%s's wanted manifest: %w", module, err)
+	}
+	return catalogue.FormChanges(running, applied), nil
+}