feat(plugin-chart-country-map): friendlier labels + auto-migrate from legacy plugin

Two small UX wins on top of the previous control-panel fixes:

1. Rename admin_level options to "World" / "Country" / "Aggregated
   regions" (from the technical "Countries (Admin 0)" / "Subdivisions
   (Admin 1)"). The control's own label becomes "Map view" with an
   explanatory description. Underlying form_data values stay 0 / 1 /
   aggregated so saved charts don't break.

2. Auto-migrate form_data when a user switches a saved legacy
   country_map chart's viz type to country_map_v2:
     - select_country: 'france'         → admin_level=1, country=FRA
     - select_country: 'france_overseas' → composite=france_overseas
     - select_country: 'turkey_regions'  → admin_level=aggregated,
                                            country=TUR, region_set=nuts_1
     - …same pattern for france_regions / italy_regions /
       philippines_regions and ~180 other legacy country files.

   The mapping lives in src/plugin/migrateFromLegacy.ts (covered by
   12 unit tests). Migration only fills fields the user hasn't already
   set on the new chart, so explicit edits win over inferred values.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

superset-frontend/plugins/plugin-chart-country-map/test/plugin/migrateFromLegacy.test.ts

@@ -0,0 +1,120 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import migrateFromLegacy from '../../src/plugin/migrateFromLegacy';
+
+test('legacy "france" → Country view with FRA pre-selected', () => {
+  expect(migrateFromLegacy({ select_country: 'france' })).toEqual({
+    admin_level: '1',
+    country: 'FRA',
+    worldview: 'ukr',
+  });
+});
+
+test('legacy "usa" → Country view with USA pre-selected', () => {
+  expect(migrateFromLegacy({ select_country: 'usa' })).toEqual({
+    admin_level: '1',
+    country: 'USA',
+    worldview: 'ukr',
+  });
+});
+
+test('legacy "uk" maps to GBR (the ISO 3166 code)', () => {
+  expect(migrateFromLegacy({ select_country: 'uk' })).toEqual({
+    admin_level: '1',
+    country: 'GBR',
+    worldview: 'ukr',
+  });
+});
+
+test('legacy "france_overseas" maps to composite, not country', () => {
+  expect(migrateFromLegacy({ select_country: 'france_overseas' })).toEqual({
+    admin_level: '1',
+    composite: 'france_overseas',
+    worldview: 'ukr',
+  });
+});
+
+test('legacy "france_regions" maps to aggregated regions for France', () => {
+  expect(migrateFromLegacy({ select_country: 'france_regions' })).toEqual({
+    admin_level: 'aggregated',
+    country: 'FRA',
+    region_set: 'regions',
+    worldview: 'ukr',
+  });
+});
+
+test('legacy "turkey_regions" maps to TUR / nuts_1', () => {
+  expect(migrateFromLegacy({ select_country: 'turkey_regions' })).toEqual({
+    admin_level: 'aggregated',
+    country: 'TUR',
+    region_set: 'nuts_1',
+    worldview: 'ukr',
+  });
+});
+
+test('legacy "italy_regions" maps to ITA / regions', () => {
+  expect(migrateFromLegacy({ select_country: 'italy_regions' })).toEqual({
+    admin_level: 'aggregated',
+    country: 'ITA',
+    region_set: 'regions',
+    worldview: 'ukr',
+  });
+});
+
+test('legacy "philippines_regions" maps to PHL / regions', () => {
+  expect(migrateFromLegacy({ select_country: 'philippines_regions' })).toEqual({
+    admin_level: 'aggregated',
+    country: 'PHL',
+    region_set: 'regions',
+    worldview: 'ukr',
+  });
+});
+
+test('uppercase / mixed case legacy values still match', () => {
+  expect(migrateFromLegacy({ select_country: 'France' })).toEqual({
+    admin_level: '1',
+    country: 'FRA',
+    worldview: 'ukr',
+  });
+});
+
+test('unknown legacy code → empty migration (user re-picks)', () => {
+  expect(migrateFromLegacy({ select_country: 'atlantis' })).toEqual({});
+});
+
+test('missing select_country → empty migration', () => {
+  expect(migrateFromLegacy({})).toEqual({});
+});
+
+test('every legacy "_regions" key resolves to an existing region_set', () => {
+  // Smoke-check that the four legacy aggregated keys all map to
+  // (country, region_set) pairs the build pipeline actually emits.
+  const cases = [
+    'france_regions',
+    'italy_regions',
+    'philippines_regions',
+    'turkey_regions',
+  ];
+  cases.forEach(name => {
+    const m = migrateFromLegacy({ select_country: name });
+    expect(m.admin_level).toBe('aggregated');
+    expect(typeof m.country).toBe('string');
+    expect(typeof m.region_set).toBe('string');
+  });
+});