Introduces passthrough.func, a Bash script to manage host-side passthrough configuration for VAAPI and NVIDIA devices in LXC containers. The script provides functions for USB, VAAPI, and NVIDIA device passthrough, including device selection dialogs, configuration file updates, and compatibility handling for privileged and unprivileged containers.
Replaces the inlined VAAPI passthrough logic in misc/build.func with calls to an external passthrough.func script, streamlining and centralizing hardware passthrough handling. Adds a new misc/passthrough.func file and introduces a hwaccel_setup_in_ct helper in misc/tools.func for hardware acceleration setup inside containers.
