Install media tools

Bootstrap the system binaries other mediaskills depend on. These scripts run in plain bash so they work before uv is installed.

When to use

First setup — run doctor.sh on a new machine or CI runner before using inspect, audio, video-transformation, etc.
Missing binary errors — when another skill returns ffmpeg not found or exit code 2.
Path debugging — use which.sh to confirm which binary the agent shell resolves.
Not for Python deps — other skills use uv run with PEP 723 inline deps; this skill only installs OS-level tools.

Script outputs always land under the workspace root .mediaskills/ — never inside .agents/skills/<skill>/:

Subfolder	Used by
`generated/`	Most skills — manifests, reports, frames, transcodes, captions, etc.
`downloads/`	`download` skill — fetched media