Initial commit: full Phases 1-6 implementation

Post-repair hardware validation pipeline for Proxmox cluster hosts.
Go orchestrator + in-image agent + mkosi live image + bundled dnsmasq
PXE + SQLite + HTMX/SSE UI + notify registry + janitor + full docs.

internal/notify/ntfy.go

@@ -0,0 +1,90 @@
+package notify
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// NtfyNotifier posts to ntfy.sh (or a self-hosted ntfy server). Message
+// body is the plain text body; title and URL are passed via X-Title and
+// X-Click headers so ntfy renders them as the push title + deep link.
+type NtfyNotifier struct {
+	NameStr string
+	Server  string // e.g. "https://ntfy.sh" or self-hosted
+	Topic   string
+	HTTP    *http.Client
+}
+
+func NewNtfy(name, server, topic string) *NtfyNotifier {
+	if server == "" {
+		server = "https://ntfy.sh"
+	}
+	return &NtfyNotifier{
+		NameStr: name,
+		Server:  strings.TrimRight(server, "/"),
+		Topic:   topic,
+		HTTP:    &http.Client{Timeout: 10 * time.Second},
+	}
+}
+
+func (n *NtfyNotifier) Name() string { return n.NameStr }
+
+func (n *NtfyNotifier) Send(ctx context.Context, ev Event) error {
+	if n.Topic == "" {
+		return fmt.Errorf("ntfy: no topic configured")
+	}
+	url := n.Server + "/" + n.Topic
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, strings.NewReader(ev.Body))
+	if err != nil {
+		return err
+	}
+	if ev.Title != "" {
+		req.Header.Set("X-Title", ev.Title)
+	}
+	if ev.URL != "" {
+		req.Header.Set("X-Click", ev.URL)
+	}
+	req.Header.Set("X-Priority", priorityForSeverity(ev.Severity))
+	req.Header.Set("X-Tags", ntfyTag(ev.Kind, ev.Severity))
+
+	resp, err := n.HTTP.Do(req)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = resp.Body.Close() }()
+	if resp.StatusCode >= 300 {
+		b, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("ntfy: %d: %s", resp.StatusCode, strings.TrimSpace(string(b)))
+	}
+	return nil
+}
+
+// priorityForSeverity maps our severities to ntfy's 1–5 scale. "info"
+// → 3 (default), warning → 4, critical → 5.
+func priorityForSeverity(s Severity) string {
+	switch s {
+	case SeverityCritical:
+		return "5"
+	case SeverityWarning:
+		return "4"
+	default:
+		return "3"
+	}
+}
+
+func ntfyTag(k Kind, s Severity) string {
+	switch {
+	case s == SeverityCritical:
+		return "rotating_light," + string(k)
+	case k == KindRunCompleted:
+		return "white_check_mark," + string(k)
+	case k == KindHoldingOpened:
+		return "construction," + string(k)
+	default:
+		return string(k)
+	}
+}