ux: inconsistent loading/empty states — bare Loading text, dual empty-state #274

Summary

Two pages show plain text "Loading…" instead of skeletons, and the empty-state implementation is duplicated across the app. This is the "same state, two different renderings" inconsistency class.

Evidence

• Loading: web/src/routes/admin/settings/+page.svelte:284 ({#if loading}Loading…{:else}…{/if}), web/src/routes/admin/calendar/+page.svelte:342 (<div class="calendar-loading">Loading calendar…</div>).
• Empty states: shared EmptyState.svelte (shadcn Empty + icon, used by schedules + analytics) vs ad-hoc .empty-state div in lib/components/DataTable.svelte:112-118 (no icon, no action slot).
• Loading rows that are fine (keep as reference): accounts, comments, mentions, dashboard, analytics, media (Skeleton), DataTable (skeleton rows), schedules (skeleton cards).

Impact

• Layout shift + inconsistent look during loads; empty tables look different from empty card grids.

Fix

• Settings: skeleton the health stat + schedule count while loading.
• Calendar: skeleton grid cells while loading.
• DataTable empty branch renders the shared EmptyState component (supports title/desc/action).

Acceptance criteria

• No page renders bare "Loading…" text.
• DataTable empty state uses the shared EmptyState component.
• Build + svelte-check clean.

Source: Titen UX audit 2026-09-20 (finding M3).