fix(build): don't fail bake progress when stdout is not a console

[locker95]

#14090 unwraps the real stdout file so Windows TTY progress works. that also feeds a redirected stdout (compose build >/dev/null) into ConsoleFromFile, which then dies with provided file is not a console.

only unwrap when stdout actually is a terminal, and fall back to plain progress otherwise.

Fixes #14182

[ndeloof]

Thanks for digging into #14182 — the analysis of the failure is right, but the fix lands in the wrong place, so we'll go with an alternative.

The root cause is a mode/stream mismatch: display.Mode resolves auto against stderr (deliberately — Compose's own progress renders there, and probing stdout would force plain on up | tee), while bake's display writes to stdout. compose build >/dev/null therefore hands bake a tty mode computed for a stream it doesn't write to.

Patching it in build_bake has two problems:

• newBakeDisplay silently downgrades an explicit --progress=tty to plain when stdout is not a console, where buildx bake (and compose's own --progress tty handling) fails loudly — auto should degrade, an explicit tty request should error.
• the makeConsole change is redundant with that fallback (progressui already falls back to plain in auto mode when the stream is not a console), and its second IsTerminal branch is unreachable in practice.

#14194 fixes the root cause instead: pass the unresolved auto to bake unless the user explicitly asked for tty, and let buildkit's progressui probe the actual output stream. That also revives the BUILDKIT_PROGRESS override, which could no longer trigger.

Closing in favor of #14194 — thanks again for the report and the repro.