foxvm rejects Windows-1252 source files: "stream did not contain valid UTF-8" #29

Visual FoxPro source files are normally saved in the ANSI code page, Windows-1252 on Western European systems. Any .prg containing an accented letter, even inside a comment, is rejected before it is parsed.

Repro

* Prezzo unità
? "città"

(saved as Windows-1252: à = byte 0xE0)

foxvm check 02_cp1252.prg → cannot read 02_cp1252.prg: stream did not contain valid UTF-8

Expected

Read source files the way VFP does: in the current code page, or one given by SET CPCOMPILE or a CLI option such as --codepage 1252. At minimum, fall back to 1252 when the input isn't valid UTF-8. The data engine already handles single-byte DBF code pages (#22); source files need the same.

Workaround

Converting copies to UTF-8 works, but then the files no longer round-trip with VFP 9, which matters while both runtimes are in use.

Environment: foxvm 0.1.0-nightly.20261007.f38230f, win-x64.