Support for mpv scripts (e.g. auto-VSR)

[rairulyle]

Feature Request

Description

Add support for loading mpv scripts in Plezy. Since Plezy uses mpv as its media player backend, it would be great to allow users to place scripts in a designated directory (e.g. scripts/) that get loaded by mpv at runtime.

Use Case

A concrete use case is enabling Auto VSR (Video Super Resolution) for NVIDIA RTX GPUs. While users can already configure mpv.conf for NVIDIA RTX features like HDR and super resolution, scripts like adaptive-gpu-scaling allow dynamic/automatic VSR behavior that can't be achieved through static config alone.

Context

As discussed in #58, Plezy's mpv backend already supports manual NVIDIA RTX configuration via mpv.conf:

vo=gpu-next
hwdec=d3d11va
vf=d3d11vpp=scale=1.3333:scaling-mode=nvidia

However, more advanced functionality like auto-scaling requires mpv Lua/JS scripts, which Plezy doesn't currently support loading.

Proposed Solution

Allow users to place mpv-compatible scripts (.lua, .js) in a directory that Plezy passes to mpv via --script-dir or --script flags. This would unlock a wide range of mpv community scripts beyond just VSR.