重构：模块化 RRPP Lite 并更新入口

lite/rrpp_core/node_api.py

@@ -0,0 +1,36 @@
+"""节点订阅的认证请求协议。"""
+
+import base64
+import json
+import urllib.error
+import urllib.request
+
+
+class NodeAuthError(Exception):
+    """订阅服务拒绝请求时携带的 HTTP 状态和用户可读原因。"""
+
+    def __init__(self, message, code=0):
+        super().__init__(message)
+        self.code = code
+
+
+def b64url(value: str) -> str:
+    """SSO 查询参数使用的无 padding URL-safe Base64。"""
+    return base64.urlsafe_b64encode(str(value).encode("utf-8")).decode("ascii").rstrip("=")
+
+
+def fetch_nodes_auth(url, user, password, timeout=10):
+    """直连拉取需 SSO 查询参数认证的 nodes.json。"""
+    opener = urllib.request.build_opener(urllib.request.ProxyHandler({}))
+    separator = "&" if "?" in url else "?"
+    request_url = f"{url}{separator}user={b64url(user)}&password={b64url(password)}"
+    try:
+        with opener.open(request_url, timeout=timeout) as response:
+            return json.loads(response.read().decode("utf-8"))
+    except urllib.error.HTTPError as error:
+        body = ""
+        try:
+            body = error.read().decode("utf-8", "replace").strip()
+        except Exception:
+            pass
+        raise NodeAuthError(body or f"请求被拒绝 (HTTP {error.code})", error.code) from None