Compose as the controller does, so a node's shadow can answer same (issue 1126, C1 C2 C3 C5 C6, T1)

Seals are reused and compared by slot (resource, field), never across resources;
one rule says which resolved config values are laid; a seat path that steps back
is owned by the seat it steps back for, whatever the seat order; a folded module
of an old-form build is composed from what runs of it; the operator export's file
is carried as it runs; a differing resource names its differing JSON paths, found
before its bodies are cut, and an answer is fitted to the node's key.

go/delivery/placement_candidate.go

@@ -163,16 +163,24 @@ type ModuleDiffers struct {
 // ResourceBodies is one differing resource of a module: its id, why, and its body composed and as it runs, masked
 // (MaskedPair); a side that does not hold it is empty.
 type ResourceBodies struct {
-	ID       string `json:"id"`
-	Why      string `json:"why"`
-	Composed string `json:"composed,omitempty"`
-	Running  string `json:"running,omitempty"`
+	ID  string `json:"id"`
+	Why string `json:"why"`
+	// Paths is every JSON path at which the two bodies differ (DifferingPaths: `sealed`, `content.url`, `links.0`), found
+	// on the whole bodies before they are cut, a JSON value written in a string read as JSON; a path names keys alone,
+	// never a value. At most MaxPaths, the last then saying how many more.
+	Paths    []string `json:"paths,omitempty"`
+	Composed string   `json:"composed,omitempty"`
+	Running  string   `json:"running,omitempty"`
 }
 
-// The bounds of a module's shown bodies.
+// The bounds of a module's shown bodies, and of one answer as the node's own key holds it: an answer over
+// MaxAnswerBytes is fitted (FitAnswer). The node's key (HaveBucket) takes a value of about 1 MiB
+// (buscompose.ChainValueBytes) and holds every group's answer beside the node's facts, so one answer keeps to a sixth.
 const (
-	MaxBodies = 20
-	MaxBody   = 8192
+	MaxBodies      = 20
+	MaxBody        = 8192
+	MaxPaths       = 64
+	MaxAnswerBytes = 160 << 10
 )
 
 // ModuleAdded is one module the candidate places on the node and the node does not run: its composition's digest when