Auto-detect TV screens in passthrough and replace with a crisp virtual display

When using passthrough mixed reality — say, sitting with family watching TV — the headset should detect television screens in view and automatically replace the low-resolution passthrough image with a crisp, high-resolution virtual display of the same content (via HDMI signal, casting, or the streaming app). This keeps the user present with family in passthrough while delivering a sharp screen, with their other apps and windows floating around it. Today this needs manual placement plus extra hardware; auto-detection would make it seamless.