Add Reset learned model to Configure

Configure now opens a menu: Settings (the previous form) or Reset learned
model. After an explicit confirmation the entry is unloaded, the learned
parts of the stored model (zone, extended and ventilation coefficients,
models kept for removed zones, Model Error and Forecast Error statistics,
fingerprints) are removed under the storage lock, and the entry is set up
again. Configuration, heat-source baselines and the window event log are
kept, and model_changes records the reset. Unloading first means no update
still running can write the old model back. English and Romanian strings;
the gust hint now refers to Model Error.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_data_quality.py

@@ -65,7 +65,12 @@ class FreshnessTests(unittest.TestCase):
     def test_freshness_settings_translated(self):
         for name in ('strings.json', 'translations/en.json', 'translations/ro.json'):
             data = json.loads((ROOT / name).read_text())
-            for section, step in (('config', 'user'), ('options', 'init')):
+            # Configure opens a menu: settings, or resetting the learned model.
+            options = data['options']
+            self.assertEqual(set(options['step']['init']['menu_options']), {'settings', 'reset_model'})
+            self.assertTrue(options['step']['reset_model']['data']['confirm_reset'])
+            self.assertEqual(set(options['abort']), {'model_reset', 'model_not_reset'})
+            for section, step in (('config', 'user'), ('options', 'settings')):
                 labels = data[section]['step'][step]['data']
                 for key in ('room_max_age_minutes', 'weather_max_age_minutes', 'room_stale_use_last_value'):
                     self.assertTrue(labels[key])