feat: AI虚拟用户新闻互动系统 v1.3.0 初始提交

- 虚拟用户管理（昵称/头像/性别/简介/邮箱同步到目标平台）
- AI互动调度（点赞/收藏/评论/转发）
- 日志时间改为北京时间
- 评论达上限后继续执行点赞收藏转发
- 一键登出全部功能
- 浅色主题UI

backend/app/utils/crypto.py

@@ -0,0 +1,49 @@
+"""AES加密工具 - 用于密码和API Key加密存储"""
+import base64
+import hashlib
+from Crypto.Cipher import AES
+from Crypto.Util.Padding import pad, unpad
+from app.core.config import settings
+
+
+def _get_key() -> bytes:
+    """获取32字节AES密钥"""
+    key = settings.AES_KEY.encode("utf-8")
+    return hashlib.sha256(key).digest()
+
+
+def encrypt(plaintext: str) -> str:
+    """AES-CBC加密"""
+    if not plaintext:
+        return ""
+    key = _get_key()
+    cipher = AES.new(key, AES.MODE_CBC)
+    ct_bytes = cipher.encrypt(pad(plaintext.encode("utf-8"), AES.block_size))
+    iv = base64.b64encode(cipher.iv).decode("utf-8")
+    ct = base64.b64encode(ct_bytes).decode("utf-8")
+    return f"{iv}:{ct}"
+
+
+def decrypt(ciphertext: str) -> str:
+    """AES-CBC解密"""
+    if not ciphertext or ":" not in ciphertext:
+        return ""
+    try:
+        iv_str, ct_str = ciphertext.split(":", 1)
+        key = _get_key()
+        iv = base64.b64decode(iv_str)
+        ct = base64.b64decode(ct_str)
+        cipher = AES.new(key, AES.MODE_CBC, iv)
+        pt = unpad(cipher.decrypt(ct), AES.block_size)
+        return pt.decode("utf-8")
+    except Exception:
+        return ""
+
+
+def mask_password(password: str) -> str:
+    """密码脱敏显示"""
+    if not password:
+        return ""
+    if len(password) <= 2:
+        return "*" * len(password)
+    return password[0] + "*" * (len(password) - 2) + password[-1]