feat(dyndns): add get_ddns_status() for os-ddclient enabled/running state

Verified against a live OPNsense 24.7 instance: the service id is
"ddclient" but the REST module is "dyndns" (/api/ddclient/* all 404).
Scoped to enabled/running only -- no ddclient/dyndns account was
configured on the test device to verify a per-account "registered IP"
shape against, so that comparison is deliberately left out rather than
guessed.

tests/unit/test_driver.py

@@ -1060,6 +1060,66 @@ class TestGetCertificates:
         driver._post = lambda path, data=None: (_ for _ in ()).throw(Exception("404"))
         assert driver.get_certificates() == []
 
+
+# ---------------------------------------------------------------------------
+# get_ddns_status()
+#
+# Endpoints verified 2026-07-15 against a live OPNsense 24.7 instance: the
+# service id is "ddclient" (get_services()) but the API module is "dyndns",
+# not "ddclient" -- /api/ddclient/* all 404, /api/dyndns/service/status and
+# /api/dyndns/settings/get are the real paths. Scoped to enabled/running
+# only: no live ddclient/dyndns account was configured on the test device
+# to verify a per-account "registered IP" shape against, so that comparison
+# is deliberately not implemented here (would be guesswork).
+# ---------------------------------------------------------------------------
+
+DYNDNS_STATUS_RESPONSE = {"status": "running"}
+DYNDNS_SETTINGS_ENABLED = {"ddclient": {"general": {"enabled": "1"}}}
+DYNDNS_SETTINGS_DISABLED = {"ddclient": {"general": {"enabled": "0"}}}
+
+
+class TestGetDdnsStatus:
+    def _fake_get(self, status_response, settings_response):
+        def fake_get(path):
+            if "service/status" in path:
+                return status_response
+            return settings_response
+
+        return fake_get
+
+    def test_calls_expected_endpoints(self, driver):
+        calls = []
+
+        def fake_get(path):
+            calls.append(path)
+            if "service/status" in path:
+                return DYNDNS_STATUS_RESPONSE
+            return DYNDNS_SETTINGS_ENABLED
+
+        driver._get = fake_get
+        driver.get_ddns_status()
+        assert calls == ["/api/dyndns/service/status", "/api/dyndns/settings/get"]
+
+    def test_enabled_and_running(self, driver):
+        driver._get = self._fake_get(DYNDNS_STATUS_RESPONSE, DYNDNS_SETTINGS_ENABLED)
+        result = driver.get_ddns_status()
+        assert result == {"enabled": True, "running": True}
+
+    def test_enabled_but_not_running(self, driver):
+        driver._get = self._fake_get({"status": "stopped"}, DYNDNS_SETTINGS_ENABLED)
+        result = driver.get_ddns_status()
+        assert result == {"enabled": True, "running": False}
+
+    def test_disabled(self, driver):
+        driver._get = self._fake_get(DYNDNS_STATUS_RESPONSE, DYNDNS_SETTINGS_DISABLED)
+        result = driver.get_ddns_status()
+        assert result == {"enabled": False, "running": True}
+
+    def test_api_error_returns_none(self, driver):
+        driver._get = lambda path: (_ for _ in ()).throw(Exception("404"))
+        assert driver.get_ddns_status() is None
+
+
 # ---------------------------------------------------------------------------
 # _post()
 # ---------------------------------------------------------------------------