feat: add all-off led action

test_led_panel.py

@@ -29,6 +29,11 @@ def main():
         (d / 'trigger').write_text('[none] timer')
         (d / 'delay_on').write_text('500')
         (d / 'delay_off').write_text('500')
+        d2 = root / 'red:power'
+        d2.mkdir()
+        (d2 / 'brightness').write_text('1')
+        (d2 / 'max_brightness').write_text('1')
+        (d2 / 'trigger').write_text('[none] timer')
         config_path = root / 'config.json'
         led_panel.LED_ROOT = root
         led_panel.CONFIG_PATH = config_path
@@ -58,7 +63,13 @@ def main():
             assert applied['ok'] and applied['applied'] == 1
             assert (d / 'brightness').read_text() == '1'
             assert (d / 'delay_on').read_text() == '123'
-            print('OK: API write + persistence regression passed')
+            all_off = req(port, '/api/all-off', {})
+            assert all_off['ok'] and all_off['changed'] == 2
+            assert (d / 'brightness').read_text() == '0'
+            assert (d2 / 'brightness').read_text() == '0'
+            assert '[none]' in (d / 'trigger').read_text() or (d / 'trigger').read_text() == 'none'
+            assert '[none]' in (d2 / 'trigger').read_text() or (d2 / 'trigger').read_text() == 'none'
+            print('OK: API write + persistence + all-off regression passed')
         finally:
             httpd.shutdown()