viewer: drop forced --hwdec=auto (froze video on frame 1)

The screen-share viewer ran mpv with --profile=low-latency (hwdec off by
default) and then forced --hwdec=auto back on. On some drivers the HW H.264
decoder stalls mid-stream: a viewer receiving a software-x264 share froze on
the first frame while audio kept playing (one MPEG-TS byte stream, so bytes
were still flowing — the video decoder gave up, the audio decoder didn't).
Screen-share H.264 at these bitrates decodes trivially in software, so leave
hwdec at the low-latency default.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/interactive.rs

@@ -281,8 +281,10 @@ impl Player {
                 &[
                     // No `--untimed`: it ignores audio timestamps and drifts a
                     // shared video out of sync. Pacing to audio keeps A/V synced.
+                    // Also leave hwdec at the `low-latency` default (software
+                    // decode): forcing `--hwdec=auto` froze some viewers on
+                    // frame 1 while audio kept playing.
                     "--profile=low-latency",
-                    "--hwdec=auto",
                     "--audio-buffer=0.2",
                     "--demuxer-max-bytes=2M",
                     "--demuxer-readahead-secs=0.5",

src/viewer/mod.rs

@@ -102,7 +102,7 @@ fn print_viewer_banner(url: &str) {
     eprintln!("│  Connected to host. Open the stream in your player:");
     eprintln!("│");
     eprintln!(
-        "│    mpv --profile=low-latency --hwdec=auto --audio-buffer=0.2 --demuxer-max-bytes=2M --demuxer-readahead-secs=0.5 {url}"
+        "│    mpv --profile=low-latency --audio-buffer=0.2 --demuxer-max-bytes=2M --demuxer-readahead-secs=0.5 {url}"
     );
     eprintln!("│    vlc --network-caching=200 --live-caching=200 {url}");
     eprintln!("│");