v0.4.0: monitoring & backup — scheduler, CPU/temp metrics, healthchecks, restic backups

Phase 2 (Monitoring & Health):
- Central job scheduler replacing ad-hoc goroutines (internal/scheduler)
- CPU usage collector via /proc/stat background sampling (internal/system/cpu_linux.go)
- Temperature reading from /sys/class/thermal + /host/sys (Docker mount)
- Load average from /proc/loadavg
- Healthchecks.io-compatible HTTP pinger (internal/monitor/pinger.go)
- System health checks: disk, memory, CPU, temp, Docker, protected containers (internal/monitor/healthcheck.go)

Phase 3 (Backups):
- Database auto-discovery via docker ps + docker inspect (internal/backup/dbdump.go)
- Database dumping via docker exec (pg_dump / mariadb-dump) with atomic writes
- Restic backup integration with auto-password generation (internal/backup/restic.go)
- Backup orchestrator: DB dumps + restic snapshots + weekly prune (internal/backup/backup.go)
- Manual backup trigger via dashboard button and POST /api/backup/run

Dashboard UI:
- CPU usage bar with load average display
- Temperature with colored indicator dot
- Backup status card with last run time, DB count, repo stats
- "Mentés most" button for manual backup trigger

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

controller/internal/system/info_linux.go

@@ -6,13 +6,16 @@ import (
 	"bufio"
 	"fmt"
 	"os"
+	"path/filepath"
+	"sort"
 	"strings"
 	"syscall"
 )
 
-// GetInfo reads system memory and disk usage.
+// GetInfo reads system memory, disk, CPU, load, and temperature info.
 // hddPath is the mount path for external HDD; if empty, HDD info is skipped.
-func GetInfo(hddPath string) SystemInfo {
+// cpuCollector provides the latest CPU usage sample; may be nil.
+func GetInfo(hddPath string, cpuCollector *CPUCollector) SystemInfo {
 	info := SystemInfo{}
 
 	// --- Memory from /proc/meminfo ---
@@ -27,6 +30,17 @@ func GetInfo(hddPath string) SystemInfo {
 		readDiskUsage(hddPath, &info.HDDTotalGB, &info.HDDUsedGB, &info.HDDAvailGB, &info.HDDPercent)
 	}
 
+	// --- Load average ---
+	readLoadAvg(&info)
+
+	// --- Temperature ---
+	readTemperature(&info)
+
+	// --- CPU from collector ---
+	if cpuCollector != nil {
+		info.CPUPercent = cpuCollector.CPUPercent()
+	}
+
 	return info
 }
 
@@ -72,7 +86,6 @@ func readMemInfo(info *SystemInfo) {
 
 // parseMemLine extracts the kB value from a /proc/meminfo line like "MemTotal:       16384000 kB"
 func parseMemLine(line string) uint64 {
-	// Remove label prefix up to ':'
 	parts := strings.SplitN(line, ":", 2)
 	if len(parts) < 2 {
 		return 0
@@ -99,7 +112,7 @@ func readDiskUsage(path string, totalGB, usedGB, availGB *float64, percent *floa
 	bsize := uint64(stat.Bsize)
 	total := stat.Blocks * bsize
 	avail := stat.Bavail * bsize
-	used := total - (stat.Bfree * bsize) // Bfree includes reserved blocks
+	used := total - (stat.Bfree * bsize)
 
 	const gb = 1024 * 1024 * 1024
 	*totalGB = float64(total) / gb
@@ -109,3 +122,117 @@ func readDiskUsage(path string, totalGB, usedGB, availGB *float64, percent *floa
 		*percent = float64(used) / float64(total) * 100
 	}
 }
+
+// readLoadAvg reads 1/5/15 minute load averages from /proc/loadavg.
+func readLoadAvg(info *SystemInfo) {
+	data, err := os.ReadFile("/proc/loadavg")
+	if err != nil {
+		return
+	}
+	fmt.Sscanf(string(data), "%f %f %f", &info.LoadAvg1, &info.LoadAvg5, &info.LoadAvg15)
+}
+
+// readTemperature reads CPU/SoC temperature from thermal zones.
+// Tries /host/sys first (Docker mount), then /sys (native).
+func readTemperature(info *SystemInfo) {
+	prefixes := []string{"/host/sys", "/sys"}
+
+	for _, prefix := range prefixes {
+		if readThermalZones(prefix, info) {
+			return
+		}
+	}
+
+	// Fallback: try hwmon
+	for _, prefix := range prefixes {
+		if readHwmon(prefix, info) {
+			return
+		}
+	}
+}
+
+func readThermalZones(sysPrefix string, info *SystemInfo) bool {
+	pattern := filepath.Join(sysPrefix, "class", "thermal", "thermal_zone*", "temp")
+	matches, err := filepath.Glob(pattern)
+	if err != nil || len(matches) == 0 {
+		return false
+	}
+
+	sort.Strings(matches)
+
+	var maxTemp float64
+	var maxSource string
+
+	for _, tempPath := range matches {
+		data, err := os.ReadFile(tempPath)
+		if err != nil {
+			continue
+		}
+
+		var milliDeg int64
+		if _, err := fmt.Sscanf(strings.TrimSpace(string(data)), "%d", &milliDeg); err != nil {
+			continue
+		}
+
+		temp := float64(milliDeg) / 1000.0
+
+		// Read the type file for the label
+		zoneDir := filepath.Dir(tempPath)
+		typePath := filepath.Join(zoneDir, "type")
+		typeData, err := os.ReadFile(typePath)
+		source := strings.TrimSpace(string(typeData))
+		if err != nil || source == "" {
+			source = filepath.Base(zoneDir)
+		}
+
+		if temp > maxTemp {
+			maxTemp = temp
+			maxSource = source
+		}
+	}
+
+	if maxTemp > 0 {
+		info.TemperatureCelsius = maxTemp
+		info.TemperatureSource = maxSource
+		return true
+	}
+	return false
+}
+
+func readHwmon(sysPrefix string, info *SystemInfo) bool {
+	pattern := filepath.Join(sysPrefix, "class", "hwmon", "hwmon*", "temp1_input")
+	matches, err := filepath.Glob(pattern)
+	if err != nil || len(matches) == 0 {
+		return false
+	}
+
+	var maxTemp float64
+	var maxSource string
+
+	for _, tempPath := range matches {
+		data, err := os.ReadFile(tempPath)
+		if err != nil {
+			continue
+		}
+
+		var milliDeg int64
+		if _, err := fmt.Sscanf(strings.TrimSpace(string(data)), "%d", &milliDeg); err != nil {
+			continue
+		}
+
+		temp := float64(milliDeg) / 1000.0
+		source := filepath.Base(filepath.Dir(tempPath))
+
+		if temp > maxTemp {
+			maxTemp = temp
+			maxSource = source
+		}
+	}
+
+	if maxTemp > 0 {
+		info.TemperatureCelsius = maxTemp
+		info.TemperatureSource = maxSource
+		return true
+	}
+	return false
+}