Initial import: nasmon health monitor, split out of home_nas

Go service (nasmon/) plus nfpm packaging (packaging/), carried over from
the home_nas monorepo. Adds rpm packaging alongside the existing deb
build (Fedora/RHEL/Rocky dependency names via nfpm overrides, per-format
systemd unit path, dpkg+rpm-compatible maintainer scripts) and a Gitea
Actions workflow that builds both formats on every push.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/collect/temps.go

@@ -0,0 +1,89 @@
+package collect
+
+import (
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+type Temp struct {
+	Chip  string  `json:"chip"`
+	Label string  `json:"label"`
+	C     float64 `json:"c"`
+}
+
+// ReadTemps lists every hwmon temperature input; falls back to thermal zones.
+func ReadTemps() []Temp {
+	temps := readHwmon("/sys/class/hwmon")
+	if len(temps) == 0 {
+		temps = readThermalZones("/sys/class/thermal")
+	}
+	sort.Slice(temps, func(i, j int) bool {
+		if temps[i].Chip != temps[j].Chip {
+			return temps[i].Chip < temps[j].Chip
+		}
+		return temps[i].Label < temps[j].Label
+	})
+	return temps
+}
+
+func readHwmon(root string) []Temp {
+	var out []Temp
+	chips, _ := filepath.Glob(filepath.Join(root, "hwmon*"))
+	for _, chip := range chips {
+		name := readTrim(filepath.Join(chip, "name"))
+		inputs, _ := filepath.Glob(filepath.Join(chip, "temp*_input"))
+		for _, in := range inputs {
+			v, err := strconv.ParseFloat(readTrim(in), 64)
+			if err != nil {
+				continue
+			}
+			base := strings.TrimSuffix(in, "_input")
+			label := readTrim(base + "_label")
+			if label == "" {
+				label = filepath.Base(base)
+			}
+			out = append(out, Temp{Chip: name, Label: label, C: v / 1000})
+		}
+	}
+	return out
+}
+
+func readThermalZones(root string) []Temp {
+	var out []Temp
+	zones, _ := filepath.Glob(filepath.Join(root, "thermal_zone*"))
+	for _, z := range zones {
+		v, err := strconv.ParseFloat(readTrim(filepath.Join(z, "temp")), 64)
+		if err != nil {
+			continue
+		}
+		out = append(out, Temp{Chip: "thermal", Label: readTrim(filepath.Join(z, "type")), C: v / 1000})
+	}
+	return out
+}
+
+// CPUTemp picks the most plausible CPU package temperature from the list.
+func CPUTemp(temps []Temp) (float64, bool) {
+	best, found := 0.0, false
+	for _, t := range temps {
+		chip := strings.ToLower(t.Chip)
+		lbl := strings.ToLower(t.Label)
+		isCPU := chip == "coretemp" || chip == "k10temp" || chip == "zenpower" ||
+			strings.Contains(lbl, "package") || strings.Contains(lbl, "tctl") || strings.Contains(lbl, "tdie") ||
+			strings.Contains(lbl, "x86_pkg_temp") || strings.Contains(lbl, "cpu")
+		if isCPU && (!found || t.C > best) {
+			best, found = t.C, true
+		}
+	}
+	return best, found
+}
+
+func readTrim(p string) string {
+	b, err := os.ReadFile(p)
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSpace(string(b))
+}