新功能(#65): 添加用户订阅限速数据层字段

Co-authored-by: multica-agent <github@multica.ai>

initialize/migrate/database/02153_user_subscribe_speed_limit.up.sql

@@ -0,0 +1,37 @@
+-- Purpose: Add user-level speed limit overrides to user_subscribe
+
+SET @column_exists = (
+  SELECT COUNT(*)
+  FROM INFORMATION_SCHEMA.COLUMNS
+  WHERE TABLE_SCHEMA = DATABASE()
+    AND TABLE_NAME = 'user_subscribe'
+    AND COLUMN_NAME = 'speed_limit'
+);
+
+SET @sql = IF(
+  @column_exists = 0,
+  'ALTER TABLE `user_subscribe` ADD COLUMN `speed_limit` int NOT NULL DEFAULT 0 COMMENT ''User-level speed limit override (Mbps, 0=use plan default)'' AFTER `upload`',
+  'SELECT ''Column speed_limit already exists in user_subscribe table'''
+);
+
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+SET @column_exists = (
+  SELECT COUNT(*)
+  FROM INFORMATION_SCHEMA.COLUMNS
+  WHERE TABLE_SCHEMA = DATABASE()
+    AND TABLE_NAME = 'user_subscribe'
+    AND COLUMN_NAME = 'traffic_limit'
+);
+
+SET @sql = IF(
+  @column_exists = 0,
+  'ALTER TABLE `user_subscribe` ADD COLUMN `traffic_limit` text DEFAULT NULL COMMENT ''User-level traffic limit rules override (JSON, NULL=use plan default)'' AFTER `speed_limit`',
+  'SELECT ''Column traffic_limit already exists in user_subscribe table'''
+);
+
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;