v0.25.0 — Debug page: operator testing & diagnostics dashboard

Debug-mode-only dashboard (/debug) with 8 collapsible sections:
system diagnostics, notification testing, backup triggers, storage
simulation, hub & connectivity, self-update dry-run, DR/setup wizard,
and in-memory log viewer. Migrates debug dump from API router to web
server. Adds ring buffer log capture, storage disconnect simulation,
event history tracking, and cross-drive/self-update test methods.

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

controller/internal/notify/notifier.go

@@ -16,6 +16,16 @@ import (
 // Notifier sends structured events to the hub via /api/v1/event.
 // Non-blocking: fires requests in goroutines, logs errors but doesn't retry aggressively.
 // Cooldown logic is handled by the Hub — the controller sends all events unconditionally.
+// EventHistoryEntry records a sent event for the debug page.
+type EventHistoryEntry struct {
+	Timestamp time.Time `json:"timestamp"`
+	EventType string    `json:"event_type"`
+	Severity  string    `json:"severity"`
+	Message   string    `json:"message"`
+	HubStatus int       `json:"hub_status"`
+	HubError  string    `json:"hub_error,omitempty"`
+}
+
 type Notifier struct {
 	hubURL     string
 	apiKey     string
@@ -28,6 +38,12 @@ type Notifier struct {
 
 	mu               sync.Mutex
 	prevHealthStatus string // tracks previous health check status for change detection
+
+	// Event history ring buffer (debug page)
+	historyMu sync.RWMutex
+	history   [50]EventHistoryEntry
+	histPos   int
+	histFull  bool
 }
 
 // New creates a new Notifier. Returns a no-op notifier if hub is not enabled.
@@ -454,6 +470,95 @@ func (n *Notifier) SendTest() error {
 	return nil
 }
 
+// ── Debug event testing ───────────────────────────────────────────────
+
+// PushTestEventSync sends a test event synchronously and returns the Hub HTTP status code.
+// Used by the debug page for event testing with configurable type/severity.
+func (n *Notifier) PushTestEventSync(eventType, severity, message string) (statusCode int, err error) {
+	if !n.enabled {
+		return 0, fmt.Errorf("hub nem konfigurált")
+	}
+
+	payload := eventRequest{
+		CustomerID: n.customerID,
+		EventType:  eventType,
+		Severity:   severity,
+		Message:    message,
+	}
+
+	jsonData, err := json.Marshal(payload)
+	if err != nil {
+		return 0, fmt.Errorf("marshal: %w", err)
+	}
+
+	url := n.hubURL + "/api/v1/event"
+	req, err := http.NewRequest("POST", url, bytes.NewReader(jsonData))
+	if err != nil {
+		return 0, fmt.Errorf("request: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+n.apiKey)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := n.httpClient.Do(req)
+	if err != nil {
+		n.recordHistory(eventType, severity, message, 0, err.Error())
+		return 0, fmt.Errorf("send: %w", err)
+	}
+	io.Copy(io.Discard, resp.Body)
+	resp.Body.Close()
+
+	if resp.StatusCode >= 400 {
+		n.recordHistory(eventType, severity, message, resp.StatusCode, fmt.Sprintf("HTTP %d", resp.StatusCode))
+		return resp.StatusCode, fmt.Errorf("hub returned %d", resp.StatusCode)
+	}
+
+	n.recordHistory(eventType, severity, message, resp.StatusCode, "")
+	return resp.StatusCode, nil
+}
+
+// GetEventHistory returns the last N event history entries (newest first).
+func (n *Notifier) GetEventHistory(limit int) []EventHistoryEntry {
+	n.historyMu.RLock()
+	defer n.historyMu.RUnlock()
+
+	total := n.histPos
+	if n.histFull {
+		total = len(n.history)
+	}
+	if limit <= 0 || limit > total {
+		limit = total
+	}
+
+	result := make([]EventHistoryEntry, 0, limit)
+	for i := 0; i < limit; i++ {
+		idx := n.histPos - 1 - i
+		if idx < 0 {
+			idx += len(n.history)
+		}
+		result = append(result, n.history[idx])
+	}
+	return result
+}
+
+// recordHistory appends an entry to the event history ring buffer.
+func (n *Notifier) recordHistory(eventType, severity, message string, hubStatus int, hubError string) {
+	n.historyMu.Lock()
+	defer n.historyMu.Unlock()
+	n.history[n.histPos] = EventHistoryEntry{
+		Timestamp: time.Now(),
+		EventType: eventType,
+		Severity:  severity,
+		Message:   message,
+		HubStatus: hubStatus,
+		HubError:  hubError,
+	}
+	n.histPos++
+	if n.histPos >= len(n.history) {
+		n.histPos = 0
+		n.histFull = true
+	}
+}
+
 // ── Backward compatibility ───────────────────────────────────────────
 
 // notifyRequest is the JSON payload for the legacy /api/v1/notify endpoint.