Lemenzo Gallery v1.19 — Large Library Performance + Premium UI

Performance
- Main Photos, Favorites, Trash and Album grids use seek/keyset MediaStore paging by INFERRED_DATE + _ID.
- Offset paging remains only for compatibility/viewer window operations.
- Album summaries and local search scan large libraries with seek paging.
- Thumbnail decoding uses a bounded 3-thread background executor and bounded queue.
- Thumbnail memory cache is capped at 48 MiB maximum.
- RecyclerView pools/cache are tuned for thumbnail-heavy scrolling and item animations are disabled.
- Recycled thumbnail views are explicitly detached from stale work.
- MediaStore change notifications are debounced to avoid refresh storms during burst captures/imports.
- First-page size reduced to 180 items with earlier prefetch for smoother startup and scrolling.
- Selecting/deselecting media updates only affected rows instead of rebinding the whole grid.

Premium LemenzoOS UI
- Palette aligned to LemenzoOS black/navy/blue design: #08090C / #0A1019 / #101722 / #3F8CFF.
- Main header, action buttons and tabs redesigned with modern Lemenzo surfaces.
- Tabs use a selected blue/navy pill state rather than a thin legacy indicator.
- Media tiles and album cards use rounded dark/navy surfaces.
- Search, Albums, Trash, Media Manager and Smart pages use the same visual system.
- Gray-heavy surfaces were replaced with blue-tinted secondary/muted colors.

Safe areas / cutout
- Added one shared SystemInsets implementation using statusBars + navigationBars + displayCutout.
- Main, About, Search, Albums, Trash, Editor, Video Editor and Media Manager use the shared safe-area handling.
- About Lemenzo Gallery now begins directly below the status bar / camera cutout instead of relying on fixed dp top padding.
- Viewer remains intentionally media-focused/full-screen and keeps its own viewer system-bar behavior.

Validation
- Static validation expanded with large-library, thumbnail-budget, safe-inset and palette invariants.
- Existing host tests retained.