Hearts of Iron IV support

[CommandGenius]

requires RenoDXHelper

[CommandGenius]

I gotta remove the debug stuff first

[Copilot]

Pull request overview

Adds a new Hearts of Iron IV (HOI4) game module to the RenoDX codebase, including shader injection and a small integration point to drive the external “RenoDXHelper” effect based on the UI nits setting.

Changes:

• Added HOI4 add-on entry point (addon.cpp) wiring up shader + swapchain mods and enabling RenoDXHelper integration.
• Introduced HOI4 shader injection definitions (shared.h) and a new pixel shader replacement implementing RenoDX tonemapping/intermediate passes.
• Extended the shared settings overlay/utilities to enable/disable RenoDXHelper and push RENODX_UI_NITS when presets/settings change.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
src/utils/settings.hpp	Adds RenoDXHelper update logic and an event hook to apply the helper once and on relevant setting changes.
src/games/hoi4/shared.h	Defines HOI4 shader injection constant buffer layout and maps it into RenoDX shader includes.
src/games/hoi4/output_0xB99B4F78.ps_5_0.hlsl	Adds the HOI4 pixel shader replacement with RenoDX tonemap + intermediate rendering integration.
src/games/hoi4/addon.cpp	New HOI4 module wiring for shader/swapchain mods and settings, including enabling RenoDXHelper usage.

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