[michiiik]

Summary

• use the portable executable directory for runtime mod discovery and configuration
• add a standalone Hello Stadium code-mod template using the existing N64Recomp .nrm pipeline
• add deterministic package verification and Windows/macOS/Linux CI
• replace the deferred modding placeholder with install, compatibility, build, and asset-policy documentation

Validation

• built the runtime-matched RecompModTool locally with MSVC
• checked the example hook source with strict Clang syntax diagnostics
• verified the hook address and size against generated/recomp_overlays.inl
• exercised the NRM verifier with valid metadata and a deliberately wrong game ID
• parsed the GitHub Actions workflow and ran git diff --check
• MIPS package production is delegated to the CI matrix's pinned LLVM 18; LLVM is not a player/runtime dependency

Closes #3