fix(captain): compare date custom attributes stored as strings in audience matcher

Custom date attributes persist as ISO strings in jsonb, so is_greater_than/
is_less_than fell into the BigDecimal branch and never matched. Parse ISO
date strings as times, mirroring Contacts::FilterService coercion.

enterprise/app/services/captain/audience_matcher.rb

@@ -100,6 +100,8 @@ class Captain::AudienceMatcher
   def compare(actual, expected)
     return nil if actual.blank?
 
+    actual = Time.zone.parse(actual) if iso_date_string?(actual)
+
     if actual.is_a?(Date) || actual.acts_like?(:time)
       actual.to_time <=> Time.zone.parse(expected.to_s)
     else
@@ -109,6 +111,14 @@ class Captain::AudienceMatcher
     nil
   end
 
+  # Custom date attributes store ISO strings in jsonb; treat them as dates the way
+  # Contacts::FilterService does (it casts them in SQL).
+  def iso_date_string?(value)
+    value.is_a?(String) && Date.iso8601(value).present?
+  rescue ArgumentError
+    false
+  end
+
   def older_than_days?(actual, days)
     date = to_date(actual)
     date.present? && date < Time.zone.today - days.to_i.days

spec/enterprise/services/captain/audience_matcher_spec.rb

@@ -61,6 +61,13 @@ RSpec.describe Captain::AudienceMatcher do
         expect(matches?(leaf('created_at', 'days_before', '30'))).to be(true)
         expect(matches?(leaf('created_at', 'days_before', '60'))).to be(false)
       end
+
+      it 'compares date custom attributes stored as ISO strings' do
+        contact.update!(custom_attributes: contact.custom_attributes.merge('signed_up_on' => '2024-01-15'))
+        expect(matches?(leaf('signed_up_on', 'is_greater_than', '2024-01-01'))).to be(true)
+        expect(matches?(leaf('signed_up_on', 'is_less_than', '2024-01-01'))).to be(false)
+        expect(matches?(leaf('signed_up_on', 'is_less_than', '2024-02-01'))).to be(true)
+      end
     end
 
     context 'with labels' do