feat(admin): 添加管理员日志查看接口

新增/api/admin/logs接口，允许管理员通过X-Admin-Token验证后查看应用日志
同时调整飞书推送日志的响应体截取长度从200增加到500字符

backend/app.py

@@ -495,6 +495,23 @@ def admin_import():
     imported = import_csv_text(raw, actor='admin')
     return jsonify({"ok": True, "imported": imported})
 
+@app.route('/api/admin/logs', methods=['GET'])
+def admin_logs():
+    token = os.getenv('ADMIN_TOKEN')
+    if token and request.headers.get('X-Admin-Token') != token:
+        return jsonify({"error": "unauthorized"}), 401
+    n = request.args.get('lines', default=200, type=int)
+    p = os.path.join(os.path.dirname(__file__), "..", "app.log")
+    if not os.path.exists(p):
+        return jsonify({"lines": []})
+    try:
+        with open(p, 'r', encoding='utf-8') as f:
+            lines = f.readlines()
+        tail = lines[-n:] if n > 0 else lines
+        return jsonify({"lines": [line.rstrip('\n') for line in tail]})
+    except Exception:
+        return jsonify({"lines": []})
+
 def auto_import_csv_on_start():
     with app.app_context():
         flag = os.getenv('AUTO_IMPORT_ON_START', '1')
@@ -628,7 +645,7 @@ def push_feishu(date_str: str, amount: float, reason: str):
         if is_feishu:
             resp = _post_json(url, payload)
             ok = (200 <= resp.status_code < 300)
-            _log(f"飞书推送卡片{'成功' if ok else '失败'}: status={resp.status_code} {resp.text[:200]}")
+            _log(f"飞书推送卡片{'成功' if ok else '失败'}: status={resp.status_code} body={resp.text[:500]}")
             if not ok:
                 post_payload = {
                     "msg_type": "post",
@@ -649,13 +666,13 @@ def push_feishu(date_str: str, amount: float, reason: str):
                 }
                 resp_post = _post_json(url, post_payload)
                 ok = (200 <= resp_post.status_code < 300)
-                _log(f"飞书推送POST{'成功' if ok else '失败'}: status={resp_post.status_code} {resp_post.text[:200]}")
+                _log(f"飞书推送POST{'成功' if ok else '失败'}: status={resp_post.status_code} body={resp_post.text[:500]}")
         if not ok:
             text = f"{shop}\n日期：{date_str}\n今日：¥{amount:.2f}"
             if isinstance(y_amt, (int, float)):
                 text += f" {arrow} {diff_str} {pct_str}".strip()
             text += f"\n原因：{reason}"
             resp2 = _post_json(url, {"msg_type":"text","content":{"text": text}})
-            _log(f"飞书推送文本{'成功' if (200 <= resp2.status_code < 300) else '失败'}: status={resp2.status_code} {resp2.text[:200]}")
+            _log(f"飞书推送文本{'成功' if (200 <= resp2.status_code < 300) else '失败'}: status={resp2.status_code} body={resp2.text[:500]}")
     except Exception as e:
         _log(f"飞书推送异常: {str(e)[:200]}")