Path.read_text() drops the final newline

Path("f").write_text("0123456789abcdef\n")
len(Path("f").read_text())   # CPython 17; v451 16

Cause and fix

lib/rtl/pathlib.pas read the file with ReadLn and joined the lines with #10, so the newline after the last line was lost, and so was every newline of a file that is only blank lines ("\n\n\n" read as "\n\n").

It now opens the file with pylib's pyfile_open, reads it whole (TPyFile.readall), closes and frees the file object, and applies the translation CPython's text mode applies on read: \r\n and a lone \r become \n, and every other byte stays as it is.

write_text already wrote the string as given, which matches CPython on Linux. This unit has no read_bytes or write_bytes, so there is no bytes round trip to check.

Measured (2026-09-29)

• test/test_nilpy_path_read_text_keeps_the_file_as_written.npy: files with and without a trailing newline, empty, blank lines only, CRLF, a lone CR, mixed endings, and a write_text(read_text()) round trip. It equals CPython on x86-64, i386 and riscv32. The previous library fails on all three. The rows are those three. wasm32 has no row: its runner has no writable directory (Runtime error 2).
• Leak check (-dPXX_ALLOC_CENSUS, tools/assert_no_leak.sh): 1000 calls leave 4 blocks live. Without the Free the file object leaked one per call (953 live).
• Not changed here: open(p).read() in text mode does NOT translate \r\n ("a\r\nb\r\n" reads as 6 chars, CPython 4). That is in LOGBOOK.