fix: try_chain support association

lib/tallty_import_export/export.rb

@@ -240,8 +240,9 @@ module TalltyImportExport
 
     def try_chain(payload, arr)
       arr.reduce(payload) do |r, m|
-        if m =~ /^\d+$/ && r.is_a?(Array) # If m is an integer string and r is an array
-          r[m.to_i]
+        if m =~ /^\d+$/
+          index = m.to_i
+          r[index] if r.is_a?(Array) || (r.respond_to?(:[]) && index < r.size) # If r is an Array or responds to :[]
         else
           r.try(m) || r.try(:[], m)
         end