fix(httpapi): paginate module nested list endpoints

Пагинация cursor/limit для CDN, AS, domain и IP range list; ответы с next_cursor и has_more по OpenAPI. Добавлен writePaginatedListJSON и тест.

Co-authored-by: Cursor <[email protected]>

internal/httpapi/list_params.go

@@ -3,6 +3,8 @@ package httpapi
 import (
 	"net/http"
 	"strconv"
+
+	"evobgp/internal/store"
 )
 
 func parseListLimit(r *http.Request) int {
@@ -22,3 +24,15 @@ func strPtrOrNull(s string) any {
 	}
 	return s
 }
+
+// writePaginatedListJSON returns a cursor/limit page as OpenAPI list envelopes (items, next_cursor, has_more).
+func writePaginatedListJSON[T any](w http.ResponseWriter, r *http.Request, all []T, toItem func(T) map[string]any) {
+	page, next, more := store.PaginateOffset(all, r.URL.Query().Get("cursor"), parseListLimit(r))
+	items := make([]map[string]any, 0, len(page))
+	for _, x := range page {
+		items = append(items, toItem(x))
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"items": items, "next_cursor": strPtrOrNull(next), "has_more": more,
+	})
+}