Convert TARGET to lowercase in the Makefile so values like PS4/PS5 match rules; update the test target to include OUTPUT_BIN and only run test binaries on linux/macos (skip otherwise). Expand README with feature notes, supported FTP commands, and ZHTTP (web file explorer) usage/security/build details. In src/pal_fileio.c, broaden the FreeBSD-style sendfile branch to also cover PLATFORM_PS4 and PLATFORM_PS5 so those platforms use the same sendfile path.