Fix Windows terminal regressions across Py version

[jserv]

This restructures _flush() so flush always runs regardless of whether os.get_blocking succeeds. The old code coupled the get_blocking probe with the flush inside single try/except OSError when the probe failed (AttributeError on Python <3.12, OSError on 3.11 console handles), the flush was skipped and nothing reached the screen.

Each operation (fileno, get_blocking, set_blocking, flush, restore) is now isolated in its own try/except, with a finally block to guarantee blocking-state restoration.

It also sets DISABLE_NEWLINE_AUTO_RETURN (0x0008) alongside VT100 in _init_windows() to prevent auto-CR on LF causing cursor drift, with graceful fallback for pre-1607 builds.

Close #48

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Summary by cubic

Fixes Windows terminal regressions across Python versions. Output now always flushes and cursor drift from LF on Windows consoles is prevented.

• Bug Fixes
  • Made _flush() robust so it always runs, even if os.get_blocking is missing or raises OSError. Steps are isolated and the blocking state is restored.
  • On Windows, enable VT100 with DISABLE_NEWLINE_AUTO_RETURN (0x0008). Fallback to VT100-only on pre-1607 builds.
  • Menuconfig: only print run() result when present. CI: added Python/version checks, console probes, and _flush() robustness tests.

^{Written for commit a675570. Summary will update on new commits.}

[jserv]

@eastWillow , Please test this pull request and determine if it works under Windows.