Add owned OpenVR media playback and stereo previews

docs/testing.md

@@ -148,3 +148,12 @@ For example, on 2026-09-27 the smoke test found that Steam's `create-shortcut`
 refuses ids with a hyphen (`missing/invalid arguments`), which the fake had
 accepted. The fake now refuses them the same way, and Frame Control makes ids
 Steam accepts.
+
+## Owned media player
+
+`tests/test_media.py` covers layout evidence and overrides, OU eye ordering,
+hardware-decoder command construction, malformed splats, stereo parallax and
+fake-Frame library/process ownership. `tests/e2e/test_media.py` checks the real
+HTTP/SSH upload and library listing without pretending the fake renders VR.
+Real decode timings and captured stereo output are recorded in
+[vr-video.md](vr-video.md). Generated media only; no external player required.