Fix BBC Launcher metadata flapping on UK channels

[mase1981]

Summary

When BBC channels display their launcher overlay, the set-top box briefly reports app state with generic "BBC Launcher" metadata, overwriting valid program information. This causes artwork and channel info to flicker and show generic launcher screen instead of actual program details.

Problem observed:

• BBC channel starts → correct artwork and media info loads
• After 2-3 seconds → reverts to "BBC Launcher" with no artwork/program info
• Logs show good metadata arriving first, then being overwritten by app state

Solution

• Cache valid linear metadata after successful linear/replay/reviewbuffer processing
• Detect launcher app overlays (name contains "launcher" or image URL contains "appstore")
• When launcher overlay detected, restore cached metadata instead of showing generic info
• Clear cache on standby/offline to prevent stale data

Changes

• lghorizon_models.py:

  • Added _last_good_linear_metadata dict to LGHorizonDeviceState
  • Added cache_linear_metadata() method
  • Added restore_linear_metadata() method
  • Added clear_linear_metadata_cache() method
  • Added static is_launcher_app() detection method

• lghorizon_device_state_processor.py:

  • Cache metadata after processing linear, reviewbuffer, and replay states
  • Check for launcher apps in _process_apps_state and restore cached data
  • Clear cache on standby/offline states

Testing

Tested with Virgin Media UK BBC channels. The integration now maintains correct program artwork and metadata when BBC Launcher overlay briefly appears.

[Sholofly]

Hi @mase1981, Sorry for the late response. Minor health issues haven taken some time.
First of all: Massive thank you for taking the time to invest to optimize the library. Highly appreciated.

I am wondering: If a program on a channel is ended, will this cause the linear meta data to stay the same? Or is it updated accordingly when a new program starts.

Please note that in my latest additions to this library, i've added some extra program information. Probably you can use that for the good :)

[mase1981]

Hey @Sholofly , i do hope you feel better now, health is more important !!

To answer your question:
Yes, metadata updates correctly when a new program starts, the library pushes new program data via MQTT and my integration picks it up.

The issue i addressed in my integeation was specifically BBC channels on Virgin Media, where the STB temporarily reports degraded metadata (BBC Launcher/No Channel/appstore image) during transitions. I built a degradation handler that caches good metadata and uses it as a bridge until valid data arrives.

And yeah, for sure, I'd love to use the extra program information you added!

I live in the US and i dont own any horizon boxes, so i do this completely blind and rely on users to provide logs and after lot of trial and error i releasse a new update, especially when you update too :)

[Sholofly]

Please resolve conflicts

[mase1981]

@Sholofly , done.

[Sholofly]

Thank you!