Fix trailer autoplay in background without resetting focus state

[kernexshadow]

Summary

This PR fixes trailer autoplay starting while the app is in the background (after pressing Home), and preserves the current focused/expanded context when returning to the app.

What changed

• Added lifecycle RESUMED gating to trailer/autoplay flows in:
  • ContentCard (classic focused/expanded poster flow)
  • ModernHomeContent (expanded card and hero trailer autoplay flow)
• Added app foreground/background event handling in detail screen flow:
  • New event: OnAppForegroundChanged
  • MetaDetailsScreen now reports lifecycle foreground changes
  • MetaDetailsViewModel cancels idle autoplay timer when app goes background
• Kept focus/expanded state intact on app resume (no forced reset to first poster/profile screen behavior from this fix).

Result

• Trailer autoplay no longer starts while the app is outside foreground.
• Returning to the app keeps the previous navigation/focus context instead of resetting it.

Closes #234