Implement r2modmanPlus-style BepInEx install rules with marker-based cache validation#11

Claude wants to merge 4 commits into

feat/new-download-extraction-handlingdanielchim/r2modmanplusplus:feat/new-download-extraction-handlingfrom

claude/fix-bepinex-install-rulesdanielchim/r2modmanplusplus:claude/fix-bepinex-install-rulesCopy head branch name to clipboard