backend v2.1: 公告管理功能 + 系统重构

- 新增 Announcement 数据模型，支持公告的增删改查
- 后台管理新增"公告管理"Tab（创建/编辑/删除/启用禁用）
- 客户端 /api/announcement 改为从数据库读取
- 账号服务重构，新增无感换号、自动分析等功能
- 新增后台任务调度器、数据库迁移脚本
- Schema/Service/Config 全面升级至 v2.1

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/services/cursor_usage_service.py

@@ -1,5 +1,5 @@
 """
-Cursor 官方用量 API 服务
+Cursor 官方用量 API 服务 v2.1
 用于验证账号有效性和查询用量信息
 """
 import httpx
@@ -7,6 +7,7 @@ import asyncio
 from typing import Optional, Dict, Any, Tuple, List
 from dataclasses import dataclass
 from datetime import datetime
+from decimal import Decimal
 
 
 @dataclass
@@ -289,27 +290,30 @@ async def get_account_usage(token: str) -> Dict[str, Any]:
     }
 
 
-async def batch_check_accounts(tokens: List[str]) -> List[Dict[str, Any]]:
+async def batch_check_accounts(tokens: List[str], max_concurrency: int = 5) -> List[Dict[str, Any]]:
     """
-    批量检查多个账号
+    批量检查多个账号（并发，带限流）
     """
-    results = []
-    for token in tokens:
-        info = await cursor_usage_service.validate_and_get_usage(token)
-        results.append({
-            "token": token[:20] + "...",  # 脱敏
-            "is_valid": info.is_valid,
-            "is_usable": info.is_usable,
-            "pool_type": info.pool_type,                      # pro/auto
-            "membership_type": info.membership_type if info.is_valid else None,
-            "days_remaining_on_trial": info.days_remaining_on_trial,
-            "plan_used": info.plan_used if info.is_valid else 0,
-            "plan_limit": info.plan_limit if info.is_valid else 0,
-            "plan_remaining": info.plan_remaining if info.is_valid else 0,
-            "total_requests": info.total_requests if info.is_valid else 0,
-            "error": info.error_message
-        })
-    return results
+    semaphore = asyncio.Semaphore(max_concurrency)
+
+    async def _check_one(token: str) -> Dict[str, Any]:
+        async with semaphore:
+            info = await cursor_usage_service.validate_and_get_usage(token)
+            return {
+                "token": token[:20] + "...",
+                "is_valid": info.is_valid,
+                "is_usable": info.is_usable,
+                "pool_type": info.pool_type,
+                "membership_type": info.membership_type if info.is_valid else None,
+                "days_remaining_on_trial": info.days_remaining_on_trial,
+                "plan_used": info.plan_used if info.is_valid else 0,
+                "plan_limit": info.plan_limit if info.is_valid else 0,
+                "plan_remaining": info.plan_remaining if info.is_valid else 0,
+                "total_requests": info.total_requests if info.is_valid else 0,
+                "error": info.error_message
+            }
+
+    return await asyncio.gather(*[_check_one(t) for t in tokens])
 
 
 async def check_and_classify_account(token: str) -> Dict[str, Any]:
@@ -335,3 +339,95 @@ async def check_and_classify_account(token: str) -> Dict[str, Any]:
         "total_requests": info.total_requests,
         "recommendation": f"建议放入 {'Pro' if info.pool_type == 'pro' else 'Auto'} 号池"
     }
+
+
+# ============ 数据库集成函数 ============
+
+def map_membership_to_account_type(membership_type: str) -> str:
+    """
+    将 Cursor API 的 membershipType 映射到 AccountType
+    """
+    mapping = {
+        "free_trial": "free_trial",
+        "pro": "pro",
+        "free": "free",
+        "business": "business",
+        "enterprise": "business",
+    }
+    return mapping.get(membership_type, "unknown")
+
+
+def calculate_usage_percent(used: int, limit: int) -> Decimal:
+    """计算用量百分比"""
+    if limit <= 0:
+        return Decimal("0")
+    return Decimal(str(round(used / limit * 100, 2)))
+
+
+async def analyze_account_from_token(token: str) -> Dict[str, Any]:
+    """
+    分析账号Token，返回所有需要更新到数据库的字段
+    用于后台分析任务
+    """
+    info = await cursor_usage_service.validate_and_get_usage(token)
+
+    if not info.is_valid:
+        return {
+            "success": False,
+            "error": info.error_message,
+            "status": "invalid"
+        }
+
+    # 计算用量百分比
+    usage_percent = calculate_usage_percent(info.plan_used, info.plan_limit)
+
+    # 确定账号状态
+    if usage_percent >= Decimal("95"):
+        status = "exhausted"
+    else:
+        status = "available"
+
+    # 解析计费周期时间
+    billing_start = None
+    billing_end = None
+    try:
+        if info.billing_cycle_start:
+            billing_start = datetime.fromisoformat(info.billing_cycle_start.replace('Z', '+00:00'))
+        if info.billing_cycle_end:
+            billing_end = datetime.fromisoformat(info.billing_cycle_end.replace('Z', '+00:00'))
+    except:
+        pass
+
+    return {
+        "success": True,
+        "status": status,
+        "account_type": map_membership_to_account_type(info.membership_type),
+        "membership_type": info.membership_type,
+        "billing_cycle_start": billing_start,
+        "billing_cycle_end": billing_end,
+        "trial_days_remaining": info.days_remaining_on_trial or 0,
+        "usage_limit": info.plan_limit,
+        "usage_used": info.plan_used,
+        "usage_remaining": info.plan_remaining,
+        "usage_percent": usage_percent,
+        "total_requests": info.total_requests,
+        "total_input_tokens": info.total_input_tokens,
+        "total_output_tokens": info.total_output_tokens,
+        "total_cost_cents": Decimal(str(info.total_cost_cents)),
+        "last_analyzed_at": datetime.now(),
+        "analyze_error": None
+    }
+
+
+async def quick_validate_token(token: str) -> Tuple[bool, Optional[str]]:
+    """
+    快速验证Token有效性（仅调用usage-summary）
+    用于激活时的快速检查
+    """
+    try:
+        resp = await cursor_usage_service.get_usage_summary(token)
+        if resp["success"]:
+            return True, None
+        return False, resp.get("error", "验证失败")
+    except Exception as e:
+        return False, str(e)