Improve Fire TV app discovery and metadata

[postigodev]

Summary

Fire TV app scanning works, but the current implementation conflates installed third-party packages with launchable apps and still derives display names from package names.

Current behavior

scan_apps() runs cmd package list packages -3, then treats every returned package as a launchable app and reports them as launchable packages. Each entry gets a display name through package-name inference.

That creates two separate problems:

• packages without a launcher activity can appear in the app catalog
• readable app names depend on package naming rather than actual app metadata

Expected outcome

Improve app discovery so the launcher contains apps Sendo can actually launch, while enriching display metadata where practical.

Acceptance criteria

• avoid presenting arbitrary third-party packages as launchable apps
• identify or validate a launchable activity/package before adding an app to the catalog
• improve display-name resolution beyond package-name inference where feasible
• keep scanning reasonably fast and preserve the existing cache flow
• degrade gracefully when richer metadata cannot be resolved

Constraints

• do not turn this into a large external metadata service
• keep ADB interaction bounded by existing timeout/reliability patterns
• preserve the simple package-based launch path where it is valid

Likely files

• crates/core/src/firetv/*
• apps/tauri/src/pages/apps.ts