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/disks.go

@@ -0,0 +1,92 @@
+package collect
+
+import (
+	"encoding/json"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type Disk struct {
+	Name   string `json:"name"` // sda
+	Path   string `json:"path"` // /dev/sda
+	Model  string `json:"model"`
+	Serial string `json:"serial"`
+	Size   uint64 `json:"size"`
+	Rota   bool   `json:"rota"`
+	Tran   string `json:"tran"` // sata, nvme, usb
+}
+
+type lsblkOut struct {
+	Blockdevices []struct {
+		Name   string   `json:"name"`
+		Path   string   `json:"path"`
+		Type   string   `json:"type"`
+		Model  string   `json:"model"`
+		Serial string   `json:"serial"`
+		Size   flexUint `json:"size"`
+		Rota   flexBool `json:"rota"`
+		Tran   string   `json:"tran"`
+	} `json:"blockdevices"`
+}
+
+// flexBool accepts true/false as well as the "1"/"0" strings older lsblk prints.
+type flexBool bool
+
+func (b *flexBool) UnmarshalJSON(data []byte) error {
+	switch strings.Trim(string(data), `"`) {
+	case "true", "1":
+		*b = true
+	default:
+		*b = false
+	}
+	return nil
+}
+
+// flexUint accepts a JSON number or a numeric string.
+type flexUint uint64
+
+func (u *flexUint) UnmarshalJSON(data []byte) error {
+	n, err := strconv.ParseUint(strings.Trim(string(data), `"`), 10, 64)
+	if err != nil {
+		*u = 0
+		return nil
+	}
+	*u = flexUint(n)
+	return nil
+}
+
+// ListDisks returns physical block devices (whole disks, no loop/zram/dm).
+func ListDisks() ([]Disk, error) {
+	b, err := run(10*time.Second, "lsblk", "-J", "-b", "-d", "-o", "NAME,PATH,TYPE,MODEL,SERIAL,SIZE,ROTA,TRAN")
+	if err != nil {
+		return nil, err
+	}
+	return parseLsblk(b)
+}
+
+func parseLsblk(b []byte) ([]Disk, error) {
+	var o lsblkOut
+	if err := json.Unmarshal(b, &o); err != nil {
+		return nil, err
+	}
+	var out []Disk
+	for _, d := range o.Blockdevices {
+		if d.Type != "disk" {
+			continue
+		}
+		if strings.HasPrefix(d.Name, "zram") || strings.HasPrefix(d.Name, "loop") ||
+			strings.HasPrefix(d.Name, "dm-") || strings.HasPrefix(d.Name, "zd") || strings.HasPrefix(d.Name, "sr") {
+			continue
+		}
+		path := d.Path
+		if path == "" {
+			path = "/dev/" + d.Name
+		}
+		out = append(out, Disk{
+			Name: d.Name, Path: path, Model: strings.TrimSpace(d.Model),
+			Serial: strings.TrimSpace(d.Serial), Size: uint64(d.Size), Rota: bool(d.Rota), Tran: d.Tran,
+		})
+	}
+	return out, nil
+}