Error states and empty UI

Every data surface needs four states: loading, empty, error, success.

Loading

• Use skeletons or spinners matching layout (table rows → row skeletons).
• Disable destructive buttons while loading.
• Avoid layout shift (reserve min-height where needed).

Empty (required quality)

Never ship bare "No data" alone. Include:

• What this list is.
• Why it might be empty (first visit vs filters).
• Primary action (e.g. "Create your first project").

<EmptyState
  title="No projects yet"
  description="Create a project to start tracking work."
  action={<Button onClick={onCreate}>New project</Button>}
/>

Differentiate filtered empty vs truly empty when filters exist.

Error

• Human-readable message (not raw error.message from API unless debug mode).
• Retry button calling refresh() / refetch().
• Log technical detail to console only in dev.

Success edge cases

• Partial load failures: show what loaded + inline error for the failed section.
• Optimistic UI: rollback on mutation failure + toast (see optimistic-updates).
• Forbidden (403): explain why instead of pretending the resource doesn't exist, where appropriate.

Checklist per list/table

• Loading UI
• Empty UI with CTA
• Error UI with retry
• No infinite spinner on failed fetch

Avoid

• Blank <div /> when data.length === 0.
• Swallowing errors silently.
• Loading forever when error is set.