Summary

Fixes the Discord application-stream handoff from League Client to the in-game League of Legends.exe process when Pengu Loader is activated through IFEO/Universal mode.

In Universal mode, Windows starts Pengu through the IFEO Debugger value as rundll32, and Pengu then creates the real LeagueClientUx.exe process. That makes LCUX appear as a child of rundll32 instead of Riot's normal launcher chain, which appears to break Discord's League Client -> game stream association.

This PR keeps the IFEO bootstrap behavior, but when _BootstrapEntry creates LeagueClientUx.exe, it uses PROC_THREAD_ATTRIBUTE_PARENT_PROCESS with the bootstrapper's inherited parent process. In local testing this made LeagueClientUx.exe appear under the normal Riot LeagueClient.exe process again instead of under rundll32.

Validation

Locally validated on Windows with Discord application streaming:

• before this change, Discord stayed on the League Client stream when entering game
• hiding or closing the client caused Discord to pause/stop the stream instead of switching
• preserving Riot's original CEF window hierarchy did not fix the handoff
• with this parent-process change, Discord successfully transitioned from League Client to the game
• process diagnostics confirmed LeagueClientUx.exe was parented to LeagueClient.exe instead of rundll32
• Release x64 core build passes with MSBuild

Notes

This is intentionally separate from the PluginFS PR. The local live test was also run with a combined PluginFS build so folder plugins could be validated at the same time, but the actual Discord fix is independent and only changes core/src/dllmain.cc.

This uses a documented Windows process creation attribute. It does not inject into the game process and does not change the game process. Reviewers should still treat this as a sensitive compatibility fix because anti-cheat/security tools can care about process ancestry.

Fixes #106.