feat: CPU SAT via stress-ng + BMC version via ipmitool

BMC:
- collector/board.go: collectBMCFirmware() via ipmitool mc info, graceful skip if /dev/ipmi0 absent
- collector/collector.go: append BMC firmware record to snap.Firmware
- app/panel.go: show BMC version in TUI right-panel header alongside BIOS

CPU SAT:
- platform/sat.go: RunCPUAcceptancePack(baseDir, durationSec) — lscpu + sensors before/after + stress-ng
- app/app.go: RunCPUAcceptancePack + RunCPUAcceptancePackResult methods, satRunner interface updated
- app/panel.go: CPU row now reads real PASS/FAIL from cpu-*/summary.txt via satStatuses(); cpuDetailResult shows last SAT summary + audit data
- tui/types.go: actionRunCPUSAT, confirmBody for CPU test with mode label
- tui/screen_health_check.go: hcCPUDurations [60,300,900]s; hcRunSingle(CPU)→confirm screen; executeRunAll uses RunCPUAcceptancePackResult
- tui/forms.go: actionRunCPUSAT → RunCPUAcceptancePackResult with mode duration
- cmd/bee/main.go: bee sat cpu [--duration N] subcommand

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

audit/internal/collector/board.go

@@ -4,6 +4,7 @@ import (
 	"bee/audit/internal/schema"
 	"bufio"
 	"log/slog"
+	"os"
 	"os/exec"
 	"strings"
 )
@@ -16,6 +17,14 @@ var execDmidecode = func(typeNum string) (string, error) {
 	return string(out), nil
 }
 
+var execIpmitool = func(args ...string) (string, error) {
+	out, err := exec.Command("ipmitool", args...).Output()
+	if err != nil {
+		return "", err
+	}
+	return string(out), nil
+}
+
 // collectBoard runs dmidecode for types 0, 1, 2 and returns the board record
 // plus the BIOS firmware entry. Any failure is logged and returns zero values.
 func collectBoard() (schema.HardwareBoard, []schema.HardwareFirmwareRecord) {
@@ -69,6 +78,45 @@ func parseBoard(type1, type2 string) schema.HardwareBoard {
 	return board
 }
 
+// collectBMCFirmware collects BMC firmware version via ipmitool mc info.
+// Returns nil if ipmitool is missing, /dev/ipmi0 is absent, or any error occurs.
+func collectBMCFirmware() []schema.HardwareFirmwareRecord {
+	if _, err := exec.LookPath("ipmitool"); err != nil {
+		return nil
+	}
+	if _, err := os.Stat("/dev/ipmi0"); err != nil {
+		return nil
+	}
+	out, err := execIpmitool("mc", "info")
+	if err != nil {
+		slog.Info("bmc: ipmitool mc info unavailable", "err", err)
+		return nil
+	}
+	version := parseBMCFirmwareRevision(out)
+	if version == "" {
+		return nil
+	}
+	slog.Info("bmc: collected", "version", version)
+	return []schema.HardwareFirmwareRecord{
+		{DeviceName: "BMC", Version: version},
+	}
+}
+
+// parseBMCFirmwareRevision extracts the "Firmware Revision" field from ipmitool mc info output.
+func parseBMCFirmwareRevision(out string) string {
+	for _, line := range strings.Split(out, "\n") {
+		line = strings.TrimSpace(line)
+		key, val, ok := strings.Cut(line, ":")
+		if !ok {
+			continue
+		}
+		if strings.TrimSpace(key) == "Firmware Revision" {
+			return strings.TrimSpace(val)
+		}
+	}
+	return ""
+}
+
 // parseBIOSFirmware extracts BIOS version from dmidecode type 0 output.
 func parseBIOSFirmware(type0 string) []schema.HardwareFirmwareRecord {
 	fields := parseDMIFields(type0, "BIOS Information")