[WIP] Store CASH_RESERVE_PCT in the autotrade settings table

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

---

This section details on the original issue you should resolve

<issue_title>Store CASH_RESERVE_PCT in the autotrade settings table</issue_title>
<issue_description>This is the amount shared between Grid trading strategy and the others. At the current 25%, we can barely open any ladders (max 2).

Since we decreased the max time bots can be stable (1.5 days only), we expect grid to be able to take a lot more funds when markets are at range, as bots opened by other strategies should close pretty soon if they don't close with set parameters.

Implementation

1. Ask Claude code to move both to autotrade_settings table

GRID_ALLOCATION_PCT = 1
CASH_RESERVE_PCT = 0

2. Create an alembic migration as a result
3. Rename SettingsDocument to BaseAutotradeConfig and update every instance using it.
4. Rename AutotradeSettingsSchema to BaseAutotradeConfigModel in pybinbot/model/autotrade_settings.py. What can we do to make sure these 2 BaseAutotradeConfig and BaseAutotradeConfigModel are always in sync?
5. As a result of this, remove AutotradeSettings = AutotradeSettingsSchema, this shouldn't be needed, all repos should be importing BaseAutotradeConfigModel instead</issue_description>

Comments on the Issue (you are @copilot in this section)