Improve portable launch, forge persistence, and operator auth UX.

Persist build extra_files for Build Manager history, print dashboard login on every start, add libp2p for Mesh P2P forge, defer WebSocket until login, and split devrun.bat from LAUNCH.bat with USB deck auto-detection.

agent/stats/reporter_linux.go

@@ -4,6 +4,7 @@ package stats
 
 import (
 	"bufio"
+	"io"
 	"os"
 	"strconv"
 	"strings"
@@ -15,8 +16,12 @@ func (r *Reporter) memoryStatus() (total, avail uint64) {
 		return 0, 0
 	}
 	defer f.Close()
+	return parseMeminfo(f)
+}
+
+func parseMeminfo(r io.Reader) (total, avail uint64) {
 	var memTotal, memAvail uint64
-	sc := bufio.NewScanner(f)
+	sc := bufio.NewScanner(r)
 	for sc.Scan() {
 		line := sc.Text()
 		if strings.HasPrefix(line, "MemTotal:") {