2be53ecd7b
utf-8-sig exists to tolerate BOMs that Windows tooling adds to files users edit. /proc and /sys files are generated by the Linux kernel, never BOM'd and absent on Windows, so -sig there only muddies the read/write policy. Switch every literal /proc/ and /sys/ read to utf-8 and teach the footgun read rule that string literals starting with /proc/ or /sys/ are exempt (user-edited files keep utf-8-sig).
