v0.12.5

look.py, scenes.py --sheet, overlay.py --text and graphics.py could crash on real Windows
FFmpeg builds (confirmed on winget's gyan.dev 9.x): drawtext's own fontconfig resolution dies
with an access violation whenever it has to resolve a font by family name, with or without a
valid fonts.conf — and doctor reported missing required: none, since -filters correctly
lists drawtext as present; the crash only ever surfaced as a runtime failure, the exact thing
the step-0 capability check exists to prevent.

• All four tools now resolve a concrete font file by default (default_font_file() in
  _common.py: a well-known system font path on Windows, fc-match on Linux/macOS) and emit
  fontfile= instead of font= whenever one can be found — fontfile= skips fontconfig
  entirely, the one form confirmed not to crash. font= remains the fallback when nothing can be
  resolved, unchanged from before.
• doctor now actually renders one frame through drawtext instead of trusting the -filters
  listing alone. A confirmed crash (killed by signal on POSIX, an access-violation-style exit on
  Windows) downgrades filter:drawtext from "listed" to missing, with the crash detail in
  errors[]; an ordinary nonzero exit proves nothing either way and leaves the listing-based
  result standing (same "unknown is not missing" principle used everywhere else in capability
  detection).
• scenes.py --sheet gained --no-timecode, matching look.py, as a way out if drawtext is
  ever genuinely unusable on a machine.
• Fixed a SyntaxWarning: invalid escape sequence '\;' in _common.py's shell_quote() (a stray
  backslash before an already-unescaped character; harmless today, an error in a future Python).
• README's Quick Start script examples now note that Windows/Git Bash needs python, not
  python3 (bin/install.js and doctor/contract already handled this; the raw examples
  didn't say so).
• SKILL.md's Gotchas section documents the crash and the fixes above.

Thanks to @willy92wins for the detailed repro in #100.

What's Changed

• fit/color/graphics/overlay: stop silently dropping subtitle/data streams by @kajisho5 in #92
• caption.py --mode mux: keep the input's existing subtitle track(s) by @kajisho5 in #94
• color.py --correct: add gamma, lift/gain, levels, and curves by @kajisho5 in #95
• stabilize.py: add --tripod and --crop (keep/black) by @kajisho5 in #97
• README: name the contract-derivation pattern SPEC by @kajisho5 in #98
• README: surface SPEC near the top by @kajisho5 in #99
• fix drawtext crash on Windows fontconfig resolution by @kajisho5 in #101

Full Changelog: v0.12.0...v0.12.5