feat(core,cli): add hardware acceleration support via --hwaccel

Add --hwaccel [METHOD] / --no-hwaccel flags to control whether -hwaccel
is passed to ffmpeg before the input file. The METHOD argument is
optional and defaults to "auto", letting ffmpeg select the best
available hardware decoder with automatic software fallback.

Hardware acceleration is enabled by default (method: auto). Users on
hosts where hwaccel causes compatibility or stability issues can opt out
with --no-hwaccel or config.toml [encoding] hwaccel = false.

The config key accepts false (disable), true (auto), or a method string
such as "vaapi" or "cuda". CLI flags take precedence as usual.

Bash completion is extended with a hwaccel_methods word list (auto,
cuda, vaapi, dxva2, d3d11va, videotoolbox, qsv) for both the space form
(--hwaccel <TAB>) and the equals form (--hwaccel=<TAB>).

The completion script is also reformatted from 4-space to 2-space
indentation for consistency with transcode.sh itself.

0 files changed, 0 insertions, 0 deletions