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/persistence_audit_unix.go

@@ -0,0 +1,59 @@
+//go:build linux
+
+package client
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func collectPersistenceAudit() PersistenceAuditReport {
+	report := PersistenceAuditReport{Platform: "linux"}
+	home, _ := os.UserHomeDir()
+	if home != "" {
+		autostart := filepath.Join(home, ".config", "autostart")
+		if entries, err := os.ReadDir(autostart); err == nil {
+			for _, e := range entries {
+				if e.IsDir() {
+					continue
+				}
+				report.Entries = append(report.Entries, PersistenceAuditEntry{
+					Kind: "xdg_autostart",
+					Name: e.Name(),
+					Detail: autostart,
+				})
+			}
+		}
+		unitDir := filepath.Join(home, ".config", "systemd", "user")
+		if entries, err := os.ReadDir(unitDir); err == nil {
+			for _, e := range entries {
+				if e.IsDir() || !strings.HasSuffix(e.Name(), ".service") {
+					continue
+				}
+				report.Entries = append(report.Entries, PersistenceAuditEntry{
+					Kind: "systemd_user",
+					Name: e.Name(),
+					Detail: unitDir,
+				})
+			}
+		}
+	}
+	out, err := exec.Command("/bin/sh", "-c", "crontab -l 2>/dev/null").CombinedOutput()
+	if err == nil {
+		for _, line := range strings.Split(string(out), "\n") {
+			line = strings.TrimSpace(line)
+			if line == "" || strings.HasPrefix(line, "#") {
+				continue
+			}
+			report.Entries = append(report.Entries, PersistenceAuditEntry{
+				Kind:   "crontab",
+				Name:   "user crontab",
+				Detail: line,
+			})
+		}
+	}
+	report.Count = len(report.Entries)
+	return report
+}