YahooFinanceProcessor.scrap_data sorts by a missing tick column

[mameikagou]

Bug

YahooFinanceProcessor.scrap_data() raises KeyError: "tick" after successfully combining downloaded frames.

Reproduction

Stub fetch_stock_data() to return frames containing the columns produced by the implementation, including day and tic, then call scrap_data() for two symbols. The final sort_values() call fails because it requests tick.

Cause

fetch_stock_data() creates a tic column, while scrap_data() sorts by ["day", "tick"].

Expected behavior

The combined frame should sort by day and tic and return normally.