fix(helpers): make timeline_view and transcribe run on Windows

[Pcecil21]

Motivation / Context

This completes the Windows-portability sweep started in #78 (cp1252 console + ffmpeg path) and #79 (subtitles-filter path escaping). Two CLI helpers were never touched by those fixes and still break on Windows.

What's fixed

helpers/timeline_view.py

• FONT_CANDIDATES listed only macOS and Linux font paths. On Windows every candidate failed Path.exists(), so load_font fell through to PIL's default bitmap font (which ignores the requested size), rendering the filmstrip labels nearly illegibly. Added %WINDIR%-derived Consolas + Arial candidates (drive-correct, not hardcoded to C:).
• Forced UTF-8 on stdout/stderr so a non-ASCII output path in the status print doesn't raise UnicodeEncodeError on a cp1252 console.

helpers/transcribe.py

• Forced UTF-8 on stdout/stderr for the same reason — it prints the video filename, which crashes the helper on Windows when the name is non-ASCII (accents, emoji, CJK).

Tests

Adds tests/test_timeline_fonts.py (cross-platform): pins the candidate list, the %WINDIR%-derived font dir, that the original POSIX candidates are preserved, and that load_font never raises. Passes on Windows and Linux.

Risk / caveats

No behavior change on macOS/Linux — the new font paths simply never match there, and the UTF-8 reconfigure is a no-op when the stream is already UTF-8. The transcribe.py JSON write was already ASCII-safe (json.dumps defaults ensure_ascii=True) and was intentionally left untouched.

🤖 Generated with Claude Code

---

Summary by cubic

Fixes Windows support for helpers by adding %WINDIR%-derived font candidates (Consolas/Arial) in timeline_view.py and forcing UTF-8 on stdout/stderr in both helpers to avoid cp1252 UnicodeEncodeError. Adds a cross-platform test to pin font candidates and ensure load_font is resilient; no behavior change on macOS/Linux.

^{Written for commit 4957119. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 3 files

_{Re-trigger cubic}