Enable Heatmap historical data on chart load

The new Heatmap module does not load any historical data, regardless of provider (CQG, dxFeed) or license (even Ultra).

Current behavior:

• Heatmap starts only when chart is opened

• All previous liquidity is missing

• Restart = full reset

This makes it impossible to analyze past order book behavior unless ATAS runs 24/7.

Important:

• This is NOT about DOM Levels

• This is about the new Heatmap module

Idea: Heatmap to load historical data on chart open (server-side or provider-based)