fix(database): 文本回放 - 统一增量表名并补齐跨库迁移清单

backend/cmd/migrate-sqlite-postgres/main.go

@@ -243,6 +243,7 @@ func migrations() []tableMigration {
 		migrateTable[model.Announcement]("announcements"),
 		migrateTable[model.UserAnnouncementRead]("user_announcement_reads"),
 		migrateTable[model.Task]("tasks"),
+		migrateTable[model.TaskTextDelta]("task_text_delta"),
 		migrateTable[model.Session]("sessions"),
 		migrateTable[model.Message]("messages"),
 		migrateTable[model.TaskLog]("task_logs"),