refactor: decompose monolithic App.tsx into per-component files

- Extract views to src/components/views/ (Overview, Logbook, Trends, Settings, Auth)
- Extract standalone components (EntryModal, ImportPreviewModal, ConfirmDialog,
  Sidebar, TopBar, MobileNav, EntryLedger, FiltersPanel, QuickAddPanel, etc.)
- Move shared helpers to src/lib (dashboard, filters, userDisplay) and static
  data to src/data (accents, quickAdds)
- App.tsx now orchestration-only (2971 -> 777 lines); no behavior change

src/components/EmptyState.tsx

@@ -0,0 +1,26 @@
+import { Plus, Zap } from "lucide-react";
+
+type EmptyStateProps = {
+  title: string;
+  copy: string;
+  actionLabel?: string;
+  onAction?: () => void;
+};
+
+export function EmptyState({ title, copy, actionLabel, onAction }: EmptyStateProps) {
+  return (
+    <div className="empty-state">
+      <div className="empty-state-icon">
+        <Zap size={22} aria-hidden="true" />
+      </div>
+      <h3 className="empty-state-title">{title}</h3>
+      <p className="empty-state-copy mt-2 max-w-sm">{copy}</p>
+      {actionLabel && onAction && (
+        <button className="primary-button mt-4" type="button" onClick={onAction}>
+          <Plus size={17} aria-hidden="true" />
+          {actionLabel}
+        </button>
+      )}
+    </div>
+  );
+}