fix: 添加缓存表定时清理任务，修复 cache_link_info 无限增长

- CacheManager 添加 cleanupExpiredCache() 方法删除过期缓存记录
- PostExecVerticle 注册每小时执行一次的定时清理任务
- 原实现只有读时惰性检查过期，过期记录永远不会被删除，长期运行后数据库持续膨胀

web-service/src/main/java/cn/qaiu/lz/common/cache/CacheManager.java

@@ -200,6 +200,31 @@ public class CacheManager {
         return promise.future();
     }
 
+    /**
+     * 清理过期缓存记录，防止数据库无限增长
+     * @return 删除的行数
+     */
+    public Future<Integer> cleanupExpiredCache() {
+        String sql = "DELETE FROM cache_link_info WHERE expiration > 0 AND expiration < #{now}";
+        Map<String, Object> params = new HashMap<>();
+        params.put("now", System.currentTimeMillis());
+        Promise<Integer> promise = Promise.promise();
+        SqlTemplate.forUpdate(jdbcPool, sql)
+                .execute(params)
+                .onSuccess(res -> {
+                    int deleted = res.rowCount();
+                    if (deleted > 0) {
+                        LOGGER.info("清理过期缓存记录 {} 条", deleted);
+                    }
+                    promise.complete(deleted);
+                })
+                .onFailure(e -> {
+                    LOGGER.error("清理过期缓存失败", e);
+                    promise.fail(e);
+                });
+        return promise.future();
+    }
+
     public Future<Map<String, Integer>> getShareKeyTotal(String shareKey) {
         String sql = """
                 SELECT `share_key`, SUM(cache_hit_total) AS hit_total, SUM(api_parser_total) AS parser_total