Add a county accessor to Mapbox geocoder results that maps to Mapbox's district context field. This follows the same pattern as the existing city/state/country methods.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: pzaich

lib/geocoder/results/mapbox.rb

@@ -19,6 +19,10 @@ def city
       data_part('place') || context_part('place')
     end
 
+    def county
+      data_part('district') || context_part('district')
+    end
+
     def state
       data_part('region') || context_part('region')
     end

test/unit/lookups/mapbox_test.rb

@@ -27,6 +27,7 @@ def test_result_components
     assert_equal "Madison Square Garden, 4 Penn Plz, New York, New York 10119, United States", result.place_name
     assert_equal "4 Penn Plz", result.street
     assert_equal "New York", result.city
+    assert_equal "New York County", result.county
     assert_equal "New York", result.state
     assert_equal "10119", result.postal_code
     assert_equal "NY", result.state_code
@@ -69,6 +70,7 @@ def test_neighborhood_result
     assert_equal "Logan Square, Chicago, Illinois, United States", result.place_name
     assert_equal nil, result.street
     assert_equal "Chicago", result.city
+    assert_equal "Cook County", result.county
     assert_equal "Illinois", result.state
     assert_equal "60647", result.postal_code
     assert_equal "IL", result.state_code
@@ -84,6 +86,7 @@ def test_postcode_result
     assert_equal "Chicago, Illinois 60647, United States", result.place_name
     assert_equal nil, result.street
     assert_equal "Chicago", result.city
+    assert_equal "Cook County", result.county
     assert_equal "Illinois", result.state
     assert_equal "60647", result.postal_code
     assert_equal "IL", result.state_code
@@ -99,6 +102,7 @@ def test_place_result
     assert_equal "Chicago, Illinois, United States", result.place_name
     assert_equal nil, result.street
     assert_equal "Chicago", result.city
+    assert_equal "Cook County", result.county
     assert_equal "Illinois", result.state
     assert_equal nil, result.postal_code
     assert_equal "IL", result.state_code
@@ -114,6 +118,7 @@ def test_region_result
     assert_equal "Illinois, United States", result.place_name
     assert_equal nil, result.street
     assert_equal nil, result.city
+    assert_equal nil, result.county
     assert_equal "Illinois", result.state
     assert_equal nil, result.postal_code
     assert_equal "IL", result.state_code
@@ -129,6 +134,7 @@ def test_country_result
     assert_equal "United States", result.place_name
     assert_equal nil, result.street
     assert_equal nil, result.city
+    assert_equal nil, result.county
     assert_equal nil, result.state
     assert_equal nil, result.postal_code
     assert_equal nil, result.state_code