Hub: add preferences sync endpoint + notification display on customer page

- POST /api/v1/preferences: accepts {customer_id, email, enabled_events} from controller
- GetRecentNotifications() store method for last N notification log entries
- Customer detail page: new Notifications section (email, events, recent log table)
- joinStrings template function for event list display

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

hub/internal/api/handler.go

@@ -44,6 +44,8 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		h.handleReport(w, r)
 	case r.Method == http.MethodPost && path == "/notify":
 		h.handleNotify(w, r)
+	case r.Method == http.MethodPost && path == "/preferences":
+		h.handleSavePreferences(w, r)
 	case r.Method == http.MethodGet && path == "/customers":
 		h.handleCustomers(w, r)
 	case r.Method == http.MethodGet && strings.HasPrefix(path, "/customers/"):
@@ -282,6 +284,44 @@ func (h *Handler) handleNotify(w http.ResponseWriter, r *http.Request) {
 	w.Write([]byte(`{"status":"ok","sent":true}`))
 }
 
+// handleSavePreferences stores notification preferences pushed from a customer controller.
+func (h *Handler) handleSavePreferences(w http.ResponseWriter, r *http.Request) {
+	// Same bearer token auth as /report and /notify
+	if h.apiKey != "" {
+		auth := r.Header.Get("Authorization")
+		if !strings.HasPrefix(auth, "Bearer ") || strings.TrimPrefix(auth, "Bearer ") != h.apiKey {
+			http.Error(w, "Unauthorized", http.StatusUnauthorized)
+			return
+		}
+	}
+
+	body, err := io.ReadAll(io.LimitReader(r.Body, 1<<20))
+	if err != nil {
+		http.Error(w, "Bad request", http.StatusBadRequest)
+		return
+	}
+
+	var payload struct {
+		CustomerID    string   `json:"customer_id"`
+		Email         string   `json:"email"`
+		EnabledEvents []string `json:"enabled_events"`
+	}
+	if err := json.Unmarshal(body, &payload); err != nil || payload.CustomerID == "" {
+		http.Error(w, "Invalid payload: customer_id required", http.StatusBadRequest)
+		return
+	}
+
+	if err := h.store.SaveNotificationPrefs(payload.CustomerID, payload.Email, payload.EnabledEvents); err != nil {
+		h.logger.Printf("[ERROR] Failed to save notification prefs for %s: %v", payload.CustomerID, err)
+		http.Error(w, "Internal error", http.StatusInternalServerError)
+		return
+	}
+
+	h.logger.Printf("[INFO] Notification preferences updated for %s: email=%s, events=%v", payload.CustomerID, payload.Email, payload.EnabledEvents)
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte(`{"status":"ok"}`))
+}
+
 // sendResendEmail sends an email via the Resend HTTP API.
 func (h *Handler) sendResendEmail(to, subject, textBody string) error {
 	payload := map[string]interface{}{

hub/internal/store/store.go

@@ -151,6 +151,43 @@ func (s *Store) LogNotification(customerID, eventType, severity, message, status
 	return err
 }
 
+// NotificationLogEntry represents a single notification log record.
+type NotificationLogEntry struct {
+	EventType    string
+	Severity     string
+	Message      string
+	Status       string // "sent", "skipped", "failed"
+	ErrorMessage string
+	CreatedAt    time.Time
+}
+
+// GetRecentNotifications returns the most recent notification log entries for a customer.
+func (s *Store) GetRecentNotifications(customerID string, limit int) ([]NotificationLogEntry, error) {
+	rows, err := s.db.Query(`
+		SELECT event_type, severity, message, status, COALESCE(error_message, ''), created_at
+		FROM notification_log
+		WHERE customer_id = ?
+		ORDER BY created_at DESC
+		LIMIT ?`, customerID, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var entries []NotificationLogEntry
+	for rows.Next() {
+		var e NotificationLogEntry
+		var createdAt, errorMsg string
+		if err := rows.Scan(&e.EventType, &e.Severity, &e.Message, &e.Status, &errorMsg, &createdAt); err != nil {
+			return nil, err
+		}
+		e.CreatedAt = parseSQLiteTime(createdAt)
+		e.ErrorMessage = errorMsg
+		entries = append(entries, e)
+	}
+	return entries, rows.Err()
+}
+
 // SaveReport stores a new report. The reportJSON should be the raw JSON payload.
 func (s *Store) SaveReport(customerID string, reportJSON []byte) error {
 	// Parse denormalized fields from the JSON

hub/internal/web/server.go

@@ -30,7 +30,8 @@ func New(store *store.Store, passwordHash string, staleThreshold time.Duration,
 		"statusColor": statusColor,
 		"statusIcon":  statusIcon,
 		"formatFloat": func(f float64) string { return fmt.Sprintf("%.0f", f) },
-		"json":        func(v interface{}) template.JS {
+		"joinStrings": func(s []string, sep string) string { return strings.Join(s, sep) },
+		"json": func(v interface{}) template.JS {
 			b, _ := json.Marshal(v)
 			return template.JS(b)
 		},
@@ -184,11 +185,17 @@ func (s *Server) handleCustomerDetail(w http.ResponseWriter, r *http.Request, cu
 	// Get history (last 24h)
 	history, _ := s.store.GetCustomerHistory(customerID, 24*time.Hour)
 
+	// Get notification preferences and recent log
+	notifPrefs, _ := s.store.GetNotificationPrefs(customerID)
+	recentNotifs, _ := s.store.GetRecentNotifications(customerID, 10)
+
 	type detailData struct {
-		Customer *store.CustomerSummary
+		Customer            *store.CustomerSummary
-		Report   map[string]interface{}
+		Report              map[string]interface{}
-		History  []store.CustomerSummary
+		History             []store.CustomerSummary
-		OverallStatus string
+		OverallStatus       string
+		NotifPrefs          *store.NotificationPrefs
+		RecentNotifications []store.NotificationLogEntry
 	}
 
 	overallStatus := "ok"
@@ -201,10 +208,12 @@ func (s *Server) handleCustomerDetail(w http.ResponseWriter, r *http.Request, cu
 	}
 
 	data := detailData{
-		Customer: customer,
+		Customer:            customer,
-		Report:   report,
+		Report:              report,
-		History:  history,
+		History:             history,
-		OverallStatus: overallStatus,
+		OverallStatus:       overallStatus,
+		NotifPrefs:          notifPrefs,
+		RecentNotifications: recentNotifs,
 	}
 
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")

hub/internal/web/templates/customer.html

@@ -155,6 +155,46 @@
             {{end}}
         </section>
 
+        <!-- Notifications -->
+        <section class="card">
+            <h2>Notifications</h2>
+            <div class="info-grid">
+                <div class="info-item">
+                    <span class="label">Email</span>
+                    <span class="value">{{if .NotifPrefs}}{{if .NotifPrefs.Email}}{{.NotifPrefs.Email}}{{else}}Not set{{end}}{{else}}Not configured{{end}}</span>
+                </div>
+                {{if .NotifPrefs}}
+                <div class="info-item">
+                    <span class="label">Events</span>
+                    <span class="value">{{if .NotifPrefs.EnabledEvents}}{{joinStrings .NotifPrefs.EnabledEvents ", "}}{{else}}None{{end}}</span>
+                </div>
+                {{end}}
+            </div>
+            {{if .RecentNotifications}}
+            <h3>Recent (last 10)</h3>
+            <table class="history-table">
+                <thead>
+                    <tr>
+                        <th>Time</th>
+                        <th>Event</th>
+                        <th>Status</th>
+                        <th>Message</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    {{range .RecentNotifications}}
+                    <tr>
+                        <td>{{.CreatedAt.Format "Jan 02 15:04"}}</td>
+                        <td>{{.EventType}}</td>
+                        <td><span class="status-badge status-badge-{{.Status}}">{{.Status}}</span></td>
+                        <td>{{.Message}}</td>
+                    </tr>
+                    {{end}}
+                </tbody>
+            </table>
+            {{end}}
+        </section>
+
         <!-- Report History (last 24h) -->
         {{if .History}}
         <section class="card">