Collect IPMI sensors, SEL and dmesg errors into audit JSON and support bundle

- audit JSON: IPMI sensor readings (ipmitool sensor) merged into hardware.sensors alongside lm-sensors data
- audit JSON: IPMI SEL entries (ipmitool sel list) in hardware.event_logs with source "ipmi-sel"
- audit JSON: dmesg error/warning lines in hardware.event_logs with source "dmesg" (filtered by error/warn/AER/Xid/NVRM/ECC/panic patterns)
- support bundle: added ipmitool-sensor.txt, ipmitool-sel.txt, ipmitool-sel-time.txt to techdump
- saa_dmi.go: fix dmiItemRE to accept SHN with parentheses (e.g. PS(4)LC for PSU fields)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/collector/dmesg_events.go

@@ -0,0 +1,129 @@
+package collector
+
+import (
+	"bee/audit/internal/schema"
+	"log/slog"
+	"os/exec"
+	"regexp"
+	"strings"
+	"time"
+)
+
+// dmesg -T output: [Thu Jun 18 14:23:45 2026] message
+// dmesg without -T: [  123.456789] message
+var dmesgTimestampRE = regexp.MustCompile(`^\[([^\]]+)\]\s*(.*)$`)
+
+// Keywords that indicate an error or hardware problem worth capturing.
+var dmesgErrorPatterns = []*regexp.Regexp{
+	regexp.MustCompile(`(?i)\berr(or)?\b`),
+	regexp.MustCompile(`(?i)\bfail(ed|ure)?\b`),
+	regexp.MustCompile(`(?i)\bfault\b`),
+	regexp.MustCompile(`(?i)\bwarn(ing)?\b`),
+	regexp.MustCompile(`(?i)\bAER\b`),
+	regexp.MustCompile(`(?i)\bXid\b`),
+	regexp.MustCompile(`(?i)\bNVRM\b`),
+	regexp.MustCompile(`(?i)\bpanic\b`),
+	regexp.MustCompile(`(?i)\bcorrected\b`),
+	regexp.MustCompile(`(?i)\buncorrect`),
+	regexp.MustCompile(`(?i)\bECC\b`),
+	regexp.MustCompile(`(?i)\btimeout\b`),
+	regexp.MustCompile(`(?i)\breset\b`),
+	regexp.MustCompile(`(?i)\bdead\b`),
+	regexp.MustCompile(`(?i)\bhang\b`),
+	regexp.MustCompile(`(?i)\bstall\b`),
+	regexp.MustCompile(`(?i)\bdisabled\b`),
+}
+
+// collectDmesgErrors runs `dmesg -T` (or `dmesg` without -T on failure) and
+// returns only lines that match known error/warning patterns.
+func collectDmesgErrors() []schema.HardwareEventLog {
+	out, err := exec.Command("dmesg", "-T").Output()
+	if err != nil || len(out) == 0 {
+		// Fallback: dmesg without human-readable timestamps
+		out, err = exec.Command("dmesg").Output()
+		if err != nil || len(out) == 0 {
+			return nil
+		}
+	}
+	entries := parseDmesgErrors(string(out))
+	if len(entries) == 0 {
+		return nil
+	}
+	slog.Info("dmesg: collected error entries", "count", len(entries))
+	return entries
+}
+
+func parseDmesgErrors(output string) []schema.HardwareEventLog {
+	var entries []schema.HardwareEventLog
+	collectedAt := time.Now().UTC().Format(time.RFC3339)
+
+	for _, line := range strings.Split(output, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+
+		var timestamp, message string
+		if m := dmesgTimestampRE.FindStringSubmatch(line); m != nil {
+			timestamp = strings.TrimSpace(m[1])
+			message = strings.TrimSpace(m[2])
+		} else {
+			message = line
+		}
+
+		if message == "" {
+			continue
+		}
+		if !matchesAny(message, dmesgErrorPatterns) {
+			continue
+		}
+
+		severity := dmesgSeverity(message)
+		source := "dmesg"
+
+		var eventTime *string
+		if timestamp != "" {
+			t := timestamp
+			eventTime = &t
+		} else {
+			eventTime = &collectedAt
+		}
+
+		entries = append(entries, schema.HardwareEventLog{
+			Source:    source,
+			EventTime: eventTime,
+			Severity:  &severity,
+			Message:   message,
+		})
+	}
+	return entries
+}
+
+func matchesAny(s string, patterns []*regexp.Regexp) bool {
+	for _, p := range patterns {
+		if p.MatchString(s) {
+			return true
+		}
+	}
+	return false
+}
+
+func dmesgSeverity(msg string) string {
+	lower := strings.ToLower(msg)
+	switch {
+	case strings.Contains(lower, "panic") ||
+		strings.Contains(lower, "aer") ||
+		strings.Contains(lower, "uncorrect") ||
+		strings.Contains(lower, "xid") ||
+		strings.Contains(lower, "nvrm"):
+		return statusCritical
+	case strings.Contains(lower, "error") ||
+		strings.Contains(lower, "fault") ||
+		strings.Contains(lower, "fail") ||
+		strings.Contains(lower, "dead") ||
+		strings.Contains(lower, "hang"):
+		return statusCritical
+	default:
+		return statusWarning
+	}
+}