feat: admin notification system with priority ordering, bell icon, and /notifications page

Two-tier notification system: new_booking (all public bookings) + pending_booking (notes/today).
Priority-sorted queue, unread count polling, enriched responses with user_name/booking_start_time.
Fix critical bug: edit_requested cleanup was broken (wrong reason string in 3 handlers).
Add 15 new tests covering priority ordering, enrichment, and notification creation flows.
Update Admin Manual, Technical Manual, and gap backlog docs.

backend/handlers/notifications/notifications.go

@@ -17,11 +17,14 @@ import (
 
 // Structs returned in JSON
 type AdminNotification struct {
-	ID        int       `json:"id"`
-	Reason    string    `json:"reason"`
-	BookingID *string   `json:"booking_id,omitempty"`
-	UserID    *string   `json:"user_id,omitempty"`
-	CreatedAt time.Time `json:"created_at"`
+	ID               int        `json:"id"`
+	Reason           string     `json:"reason"`
+	BookingID        *string    `json:"booking_id,omitempty"`
+	UserID           *string    `json:"user_id,omitempty"`
+	UserName         *string    `json:"user_name,omitempty"`
+	BookingStartTime *time.Time `json:"booking_start_time,omitempty"`
+	AcknowledgedAt   *time.Time `json:"acknowledged_at,omitempty"`
+	CreatedAt        time.Time  `json:"created_at"`
 }
 
 type AdminNotificationListResponse struct {
@@ -32,6 +35,10 @@ type AdminNotificationListResponse struct {
 }
 
 // GET /api/admin/notifications
+// Query params:
+//   page, per_page — pagination (default page=1, per_page=20)
+//   include_acknowledged — if "true", returns all notifications sorted newest-first.
+//     Default (false/omitted): only unacknowledged, sorted by priority then oldest-first.
 func GetNotifications(w http.ResponseWriter, r *http.Request) {
 	// Parse query params
 	page := 1
@@ -44,33 +51,61 @@ func GetNotifications(w http.ResponseWriter, r *http.Request) {
 		perPage = pp
 	}
 
+	includeAcknowledged := r.URL.Query().Get("include_acknowledged") == "true"
 	reasonFilter := r.URL.Query().Get("reason")
 
 	baseQuery := `
-		SELECT id, reason, booking_id, user_id, created_at
-		FROM admin_notifications
-		WHERE acknowledged_at IS NULL
+		SELECT an.id, an.reason, an.booking_id, an.user_id,
+		       u.n_first_name || ' ' || u.n_last_name AS user_name,
+		       b.start_time AS booking_start_time,
+		       an.acknowledged_at, an.created_at
+		FROM admin_notifications an
+		LEFT JOIN users u ON an.user_id = u.id
+		LEFT JOIN bookings b ON an.booking_id = b.id
 `
 	countQuery := `
 		SELECT COUNT(*) FROM admin_notifications
-		WHERE acknowledged_at IS NULL
 `
 
 	args := []any{}
 	countArgs := []any{}
 	param := 1
 
-	// Optional reason filter
+	if !includeAcknowledged {
+		baseQuery += fmt.Sprintf(" WHERE an.acknowledged_at IS NULL")
+		countQuery += ` WHERE acknowledged_at IS NULL`
+	}
+
 	if reasonFilter != "" {
-		baseQuery += fmt.Sprintf(" AND reason = $%d", param)
-		countQuery += fmt.Sprintf(" AND reason = $%d", param)
+		if !includeAcknowledged {
+			baseQuery += fmt.Sprintf(" AND an.reason = $%d", param)
+			countQuery += fmt.Sprintf(" AND reason = $%d", param)
+		} else {
+			baseQuery += fmt.Sprintf(" WHERE an.reason = $%d", param)
+			countQuery += fmt.Sprintf(" WHERE reason = $%d", param)
+		}
 		args = append(args, reasonFilter)
 		countArgs = append(countArgs, reasonFilter)
 		param++
 	}
 
-	// ORDER & pagination
-	baseQuery += " ORDER BY created_at DESC"
+	if includeAcknowledged {
+		baseQuery += " ORDER BY an.created_at DESC"
+	} else {
+		baseQuery += ` ORDER BY CASE an.reason
+			WHEN 'pending_booking' THEN 1
+			WHEN 'cancelled_booking' THEN 2
+			WHEN 'late_cancellation' THEN 3
+			WHEN 'no_deposit' THEN 4
+			WHEN 'deposit_paid' THEN 5
+			WHEN 'affiliate_claim' THEN 6
+			WHEN 'edit_requested' THEN 7
+			WHEN 'new_booking' THEN 8
+			WHEN '1_month_no_pay' THEN 9
+			WHEN '1_week_no_pay' THEN 10
+			ELSE 11
+		END, an.created_at ASC`
+	}
 	baseQuery += fmt.Sprintf(" LIMIT $%d OFFSET $%d", param, param+1)
 	args = append(args, perPage, (page-1)*perPage)
 
@@ -95,15 +130,21 @@ func GetNotifications(w http.ResponseWriter, r *http.Request) {
 	notifications := []AdminNotification{}
 
 	for rows.Next() {
-	var n AdminNotification
+		var n AdminNotification
 		var bookingID sql.NullString
 		var userID sql.NullString
+		var userName sql.NullString
+		var bookingStartTime sql.NullTime
+		var acknowledgedAt sql.NullTime
 
 		err := rows.Scan(
 			&n.ID,
 			&n.Reason,
 			&bookingID,
 			&userID,
+			&userName,
+			&bookingStartTime,
+			&acknowledgedAt,
 			&n.CreatedAt,
 		)
 		if err != nil {
@@ -118,6 +159,15 @@ func GetNotifications(w http.ResponseWriter, r *http.Request) {
 		if userID.Valid {
 			n.UserID = &userID.String
 		}
+		if userName.Valid {
+			n.UserName = &userName.String
+		}
+		if bookingStartTime.Valid {
+			n.BookingStartTime = &bookingStartTime.Time
+		}
+		if acknowledgedAt.Valid {
+			n.AcknowledgedAt = &acknowledgedAt.Time
+		}
 
 		notifications = append(notifications, n)
 	}
@@ -137,6 +187,27 @@ func GetNotifications(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// GET /api/admin/notifications/unread-count
+// Returns the count of unacknowledged notifications for the bell icon.
+func GetUnreadCount(w http.ResponseWriter, r *http.Request) {
+	var count int
+	err := db.DB.QueryRow(r.Context(),
+		`SELECT COUNT(*) FROM admin_notifications WHERE acknowledged_at IS NULL`,
+	).Scan(&count)
+	if err != nil {
+		log.Printf("Failed to count unread notifications: %v", err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(map[string]int{"count": count}); err != nil {
+		log.Printf("Failed to encode response: %v", err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+}
+
 func AcknowledgeNotification(w http.ResponseWriter, r *http.Request) {
 	idStr := chi.URLParam(r, "id")
 	if idStr == "" {