feat(launcher): add mpv args passthrough

docs-site/launcher-script.md

@@ -91,6 +91,7 @@ Use `subminer <subcommand> -h` for command-specific help.
 | `-S, --start-overlay` | Explicitly start overlay after mpv launches         |
 | `-T, --no-texthooker` | Disable texthooker server                           |
 | `-p, --profile`       | mpv profile name (default: `subminer`)              |
+| `-a, --args`          | Pass additional mpv arguments as a quoted string      |
 | `-b, --backend`       | Force window backend (`hyprland`, `sway`, `x11`)    |
 | `--log-level`         | Logger verbosity (`debug`, `info`, `warn`, `error`) |
 | `--dev`, `--debug`    | Enable app dev-mode (not tied to log level)         |

docs-site/usage.md

@@ -56,6 +56,7 @@ subminer ytsearch:"jp news"       # Play first YouTube search result
 subminer --setup                  # Open first-run setup popup
 subminer --log-level debug video.mkv # Enable verbose logs for launch/debugging
 subminer --log-level warn video.mkv  # Set logging level explicitly
+subminer --args '--fs=opengl-hq --ytdl-format=bestvideo*+bestaudio/best' video.mkv  # Pass extra mpv args
 
 # Options
 subminer -T video.mkv             # Disable texthooker server
@@ -189,6 +190,8 @@ Top-level launcher flags like `--jellyfin-*` and `--yt-subgen-*` are intentional
 - `--secondary-sid=auto`
 - `--secondary-sub-visibility=no`
 
+You can append additional MPV arguments with launcher `-a/--args`, for example `--args "--ao=alsa --volume=80"`.
+
 You can define a matching profile in `~/.config/mpv/mpv.conf` for consistency when launching `mpv` manually or from other tools. `subminer` launches with `--profile=subminer` by default (or override with `subminer -p <profile> ...`):
 
 ```ini