Persist per-game PS2RD cheat selections

[maddogx2x]

Summary

Adds persistent per-game PS2RD cheat selections to OPL's existing game configuration files.

Selections are stored by normalized cheat name rather than list position, so they remain stable when cheat databases are reordered. Required/master codes remain enabled and cannot be toggled off, while optional cheats default to disabled when no saved selection exists.

Changes

• Store enabled optional cheats as numbered $CheatSelNNN values in the per-game CFG.
• Restore selections by normalized cheat name.
• Recognize Mastercode, Master Code, and Enable Code (Must Be On) as required-code headings.
• Keep required codes enabled and locked in the selector.
• Default optional cheats to OFF in select mode.
• Preserve the existing automatic enable-all cheat mode.
• Save selections when the user starts the game.
• Centralize persistence behavior in cheatconfig.c and cheatconfig.h.

Scope

This pull request intentionally excludes project-specific behavior:

• No PSBBN auto-launch handling.
• No ATA or BDM default changes.
• No launcher-specific logic.
• No paging changes.
• No separate save-only button behavior.

Testing status

The earlier implementation of the persistence behavior was hardware-tested successfully on PS2 hardware, including saving and restoring selections by cheat name and enforcing the required code.

This branch is a refactored port against the current upstream master. The refactored source was previously compiler-verified through final ELF linkage on the Beta-2245 base, but this exact current-upstream branch has not yet been hardware-tested. The PR is therefore opened as a draft pending maintainer review and hardware validation.

Source project

Development source and documentation:

https://github.com/maddogx2x/OPL-Cheat-Persistence

[maddogx2x]

I there's anything that needs changing please let me know.

Thanks.