Replaces ad-hoc "Loading…" text and bare empty messages with two
shared feedback primitives that carry subtle lucide icons, consistent
muted-foreground/destructive tones, and a11y signaling (role=status,
aria-busy, role=alert on destructive empties). Loading copy gains
context ("Loading photos/folders/heaps/metadata…") and the right-
sidebar idle state moves from a "ⓘ" glyph to a MousePointerClick
icon. SkeletonGrid stays as the initial-grid loader.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
