feat(server-sdk): 移除服务端SDK的login方法，服务端SDK不应包含登录概念

im-sdk/src/main/java/com/xuqm/im/sdk/XuqmImServerSdk.java

@@ -62,30 +62,6 @@ public final class XuqmImServerSdk {
         return new Builder();
     }
 
-    public LoginResponse login(String userId) {
-        long timestamp = System.currentTimeMillis();
-        String nonce = UUID.randomUUID().toString().replace("-", "");
-        String payload = AppRequestSignatureUtil.payload(appId, userId, timestamp, nonce);
-        String signature = AppRequestSignatureUtil.sign(appSecret, payload);
-        URI uri = buildUri(
-                "/api/im/auth/login",
-                loginQuery(userId, timestamp, nonce)
-        );
-        ApiResponse<LoginResponse> response = request(
-                "POST",
-                uri,
-                null,
-                Map.of(
-                        "X-App-Id", appId,
-                        "X-App-Timestamp", String.valueOf(timestamp),
-                        "X-App-Nonce", nonce,
-                        "X-App-Signature", signature
-                ),
-                new TypeReference<>() {}
-        );
-        return response.data();
-    }
-
     public ImMessage sendMessage(SendMessageRequest request) {
         ApiResponse<ImMessage> response = request(
                 "POST",
@@ -1379,15 +1355,6 @@ public final class XuqmImServerSdk {
         return URI.create(builder.toString());
     }
 
-    private Map<String, String> loginQuery(String userId, long timestamp, String nonce) {
-        Map<String, String> query = new LinkedHashMap<>();
-        query.put("appId", appId);
-        query.put("userId", userId);
-        query.put("timestamp", String.valueOf(timestamp));
-        query.put("nonce", nonce);
-        return query;
-    }
-
     private Map<String, String> appQuery() {
         Map<String, String> query = new LinkedHashMap<>();
         query.put("appId", appId);