fix: detect otc chain u discount spam

rules/spam_regex.txt

@@ -8,3 +8,7 @@
 (?:USDT|U\s?S\s?D\s?T|泰达币|虚拟币|币圈|搬砖|套利).{0,18}(?:赚钱|收益|项目|加我|看主页|进群)|85
 (?:贷款|借款|套现|信用卡|花呗|白条|提额|下款|黑户|征信).{0,18}(?:秒批|当天|无视|包过|渠道)|85
 (?:t\.me|telegram\.me|tg://|飞机群).{0,40}(?:join|group|channel|\+|进群|频道)|95
+# OTC/链U/下浮点位灰产
+(?:链\s*[uU]|[uU]\s*链|欧美链|链上\s*[uU]|出\s*[uU]|收\s*[uU]).{0,30}(?:下浮|折扣|点位|\d+\s*%|\d+\s*-\s*\d+\s*%|懂的来|懂的)|95
+(?:下浮|折扣|低价).{0,16}(?:\d+\s*%|\d+\s*-\s*\d+\s*%).{0,20}(?:出|收|[uU]|链)|90
+(?:大量|批量).{0,8}(?:欧美链|链\s*[uU]|[uU]\s*链|出\s*[uU]).{0,30}(?:懂的来|下浮|点位|折扣)|90