Elden Ring under Proton on Linux is the same Windows binary, so every
AOB signature and memory offset is unchanged — only how the process
gets found and read differs. Split main.go/i18n.go (previously
Windows-only) into a portable process.go (signature scanning, pointer
resolution, the poll loop) plus process_windows.go/process_linux.go
behind a small boundary: findProcessID, openProcess,
closeProcessHandle, readMemory, findModuleBase, productVersion,
systemLang.
Linux side: finds the process by walking /proc/*/maps for a mapping
ending in eldenring.exe (Proton runs several helper processes, so
matching by name alone isn't reliable), reads memory via
/proc/<pid>/mem (stdlib only, no external deps), and has no
productVersion equivalent (returns ok=false — this was always just a
hint for which PlayerIns offset to try first; the real one is
confirmed by a live memory read regardless). openProcess probes
/proc/<pid>/mem up front so a ptrace_scope permission failure surfaces
immediately with the exact `sudo setcap cap_sys_ptrace+ep <path>` fix,
never suggesting the system-wide ptrace_scope=0 weakening or running
as root.
main.go and i18n.go are fully portable now, no build tags. Verified:
Windows build/vet/test plus a real run (no regression from moving
~500 lines). Linux is cross-compile build/vet only in this session —
not yet run against a real Proton process.
