dns: switch to active upstream pool and wave fallback behavior

selective-vpn-gui/api_client.py

@@ -259,6 +259,11 @@ class DNSBenchmarkResponse:
     recommended_meta: List[str]
 
 
+@dataclass(frozen=True)
+class DNSUpstreamPoolState:
+    items: List[DNSBenchmarkUpstream]
+
+
 @dataclass(frozen=True)
 class SmartdnsServiceState:
     state: str
@@ -1185,6 +1190,48 @@ class ApiClient:
             },
         )
 
+    def dns_upstream_pool_get(self) -> DNSUpstreamPoolState:
+        data = cast(Dict[str, Any], self._json(self._request("GET", "/api/v1/dns/upstream-pool")) or {})
+        raw = data.get("items") or []
+        if not isinstance(raw, list):
+            raw = []
+        items: List[DNSBenchmarkUpstream] = []
+        for row in raw:
+            if not isinstance(row, dict):
+                continue
+            addr = str(row.get("addr") or "").strip()
+            if not addr:
+                continue
+            items.append(DNSBenchmarkUpstream(addr=addr, enabled=bool(row.get("enabled", True))))
+        return DNSUpstreamPoolState(items=items)
+
+    def dns_upstream_pool_set(self, items: List[DNSBenchmarkUpstream]) -> DNSUpstreamPoolState:
+        data = cast(
+            Dict[str, Any],
+            self._json(
+                self._request(
+                    "POST",
+                    "/api/v1/dns/upstream-pool",
+                    json_body={
+                        "items": [{"addr": u.addr, "enabled": bool(u.enabled)} for u in (items or [])],
+                    },
+                )
+            )
+            or {},
+        )
+        raw = data.get("items") or []
+        if not isinstance(raw, list):
+            raw = []
+        out: List[DNSBenchmarkUpstream] = []
+        for row in raw:
+            if not isinstance(row, dict):
+                continue
+            addr = str(row.get("addr") or "").strip()
+            if not addr:
+                continue
+            out.append(DNSBenchmarkUpstream(addr=addr, enabled=bool(row.get("enabled", True))))
+        return DNSUpstreamPoolState(items=out)
+
     def dns_benchmark(
         self,
         upstreams: List[DNSBenchmarkUpstream],