mesh-build-go publishes the build runner as its own package, so the other build modules share it without mesh-sdk (ADR 0593 §1)

The runner, the toolchain guard, the fetch, the parsers, buildcpu, the conformance kit and mesh-pack move from mesh-sdk's
buildstep into modules/mesh-build-go/buildstep (own go.mod). mesh-build-go, mesh-build-node and mesh-build-image require it
by a same-repository replace; what the delivery parts read (the failure contract, the fetch request, the stale sweep, the
module tree shape, NewID, CapacitySetting) stays imported from mesh-sdk as sdkstep.

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

modules/mesh-build-node/cmd/mesh-build-node/module.go

@@ -8,7 +8,8 @@ import (
 	"sync"
 	"time"
 
-	"git.novox.be/novox/mesh-sdk/go/buildstep"
+	"git.novox.be/novox/mesh-catalog/modules/mesh-build-go/buildstep"
+	sdkstep "git.novox.be/novox/mesh-sdk/go/buildstep"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/forgekey"
 	"git.novox.be/novox/mesh-sdk/go/health"
@@ -68,7 +69,7 @@ type Module struct {
 	// sets floorOf(node), and a zero Floor checks nothing.
 	Floor buildstep.Floor
 
-	// Settings is the module's settings file, which holds the node's build capacity (buildstep.CapacitySetting); Capacity,
+	// Settings is the module's settings file, which holds the node's build capacity (sdkstep.CapacitySetting); Capacity,
 	// when set, answers it instead (a test).
 	Settings string
 	Capacity func() int
@@ -139,7 +140,7 @@ func (m *Module) Start(ctx context.Context) {
 			m.Say("the toolchain: %v", err)
 		}
 		m.CleanWorkspaces(m.now())
-		buildstep.EndStaleRound(m.stepScan(), m.Node, m.Say) // asks past the step bound, on the module's own round (issue 1890)
+		sdkstep.EndStaleRound(m.stepScan(), m.Node, m.Say) // asks past the step bound, on the module's own round (issue 1890)
 		select {
 		case <-ctx.Done():
 			return