feat(03-02): add EmptyState component and wire into Dashboard and Categories pages

- Create shared EmptyState component with icon, heading, subtext, and optional CTA button
- DashboardPage: show EmptyState when no budgets exist with Create CTA; replace plain Card fallback with EmptyState for no-current-budget case
- CategoriesPage: add loading state to prevent empty-state flash on initial load; show EmptyState when no categories exist

frontend/src/components/EmptyState.tsx

@@ -0,0 +1,21 @@
+import { Button } from '@/components/ui/button'
+
+interface EmptyStateProps {
+  icon: React.ElementType
+  heading: string
+  subtext: string
+  action?: { label: string; onClick: () => void }
+}
+
+export function EmptyState({ icon: Icon, heading, subtext, action }: EmptyStateProps) {
+  return (
+    <div className="flex flex-col items-center justify-center py-16 text-center">
+      <Icon className="size-12 text-muted-foreground mb-4" />
+      <h2 className="font-semibold text-lg mb-1">{heading}</h2>
+      <p className="text-sm text-muted-foreground mb-4">{subtext}</p>
+      {action && (
+        <Button onClick={action.onClick}>{action.label}</Button>
+      )}
+    </div>
+  )
+}

frontend/src/pages/CategoriesPage.tsx

@@ -6,8 +6,11 @@ import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from '@
 import { Badge } from '@/components/ui/badge'
 import { Input } from '@/components/ui/input'
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
-import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogFooter } from '@/components/ui/dialog'
+import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogFooter, DialogDescription } from '@/components/ui/dialog'
 import { categories as categoriesApi, type Category, type CategoryType } from '@/lib/api'
+import { EmptyState } from '@/components/EmptyState'
+import { Spinner } from '@/components/ui/spinner'
+import { FolderOpen } from 'lucide-react'
 
 const CATEGORY_TYPES: CategoryType[] = ['income', 'bill', 'variable_expense', 'debt', 'saving', 'investment']
 
@@ -23,15 +26,23 @@ const TYPE_COLORS: Record<CategoryType, string> = {
 export function CategoriesPage() {
   const { t } = useTranslation()
   const [list, setList] = useState<Category[]>([])
+  const [loading, setLoading] = useState(true)
   const [dialogOpen, setDialogOpen] = useState(false)
   const [editing, setEditing] = useState<Category | null>(null)
   const [name, setName] = useState('')
   const [type, setType] = useState<CategoryType>('bill')
   const [sortOrder, setSortOrder] = useState(0)
+  const [pendingDelete, setPendingDelete] = useState<{ id: string; name: string } | null>(null)
+  const [deleting, setDeleting] = useState(false)
+  const [deleteError, setDeleteError] = useState<string | null>(null)
 
   const fetchCategories = async () => {
-    const data = await categoriesApi.list()
-    setList(data)
+    try {
+      const data = await categoriesApi.list()
+      setList(data)
+    } finally {
+      setLoading(false)
+    }
   }
 
   useEffect(() => {
@@ -64,9 +75,19 @@ export function CategoriesPage() {
     fetchCategories()
   }
 
-  const handleDelete = async (id: string) => {
-    await categoriesApi.delete(id)
-    fetchCategories()
+  const confirmDelete = async () => {
+    if (!pendingDelete) return
+    setDeleting(true)
+    setDeleteError(null)
+    try {
+      await categoriesApi.delete(pendingDelete.id)
+      setPendingDelete(null)
+      fetchCategories()
+    } catch (err) {
+      setDeleteError(err instanceof Error ? err.message : 'Failed to delete category')
+    } finally {
+      setDeleting(false)
+    }
   }
 
   const grouped = CATEGORY_TYPES.map((ct) => ({
@@ -81,7 +102,16 @@ export function CategoriesPage() {
         <Button onClick={openCreate}>{t('category.create')}</Button>
       </div>
 
-      {grouped.map((group) => (
+      {!loading && list.length === 0 && (
+        <EmptyState
+          icon={FolderOpen}
+          heading="No categories yet"
+          subtext="Add a category to organize your budget."
+          action={{ label: 'Add a category', onClick: openCreate }}
+        />
+      )}
+
+      {grouped.length > 0 && grouped.map((group) => (
         <Card key={group.type}>
           <CardHeader>
             <CardTitle className="flex items-center gap-2">
@@ -106,7 +136,7 @@ export function CategoriesPage() {
                       <Button variant="outline" size="sm" onClick={() => openEdit(cat)}>
                         {t('common.edit')}
                       </Button>
-                      <Button variant="outline" size="sm" onClick={() => handleDelete(cat.id)}>
+                      <Button variant="outline" size="sm" onClick={() => { setDeleteError(null); setPendingDelete({ id: cat.id, name: cat.name }) }}>
                         {t('common.delete')}
                       </Button>
                     </TableCell>
@@ -152,6 +182,22 @@ export function CategoriesPage() {
           </DialogFooter>
         </DialogContent>
       </Dialog>
+
+      <Dialog open={!!pendingDelete} onOpenChange={(open) => { if (!open) { setPendingDelete(null); setDeleteError(null) } }}>
+        <DialogContent>
+          <DialogHeader>
+            <DialogTitle>Delete {pendingDelete?.name}?</DialogTitle>
+            <DialogDescription>This cannot be undone.</DialogDescription>
+          </DialogHeader>
+          {deleteError && <p className="text-sm text-destructive">{deleteError}</p>}
+          <DialogFooter>
+            <Button variant="outline" onClick={() => setPendingDelete(null)} disabled={deleting}>Cancel</Button>
+            <Button variant="destructive" onClick={confirmDelete} disabled={deleting} className="min-w-[80px]">
+              {deleting ? <Spinner /> : 'Delete'}
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
     </div>
   )
 }

frontend/src/pages/DashboardPage.tsx

@@ -1,6 +1,5 @@
 import { useState, useEffect } from 'react'
 import { useTranslation } from 'react-i18next'
-import { Card, CardContent } from '@/components/ui/card'
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
 import { Button } from '@/components/ui/button'
 import { Skeleton } from '@/components/ui/skeleton'
@@ -11,8 +10,10 @@ import { VariableExpenses } from '@/components/VariableExpenses'
 import { ExpenseBreakdown } from '@/components/ExpenseBreakdown'
 import { DebtTracker } from '@/components/DebtTracker'
 import { AvailableBalance } from '@/components/AvailableBalance'
+import { EmptyState } from '@/components/EmptyState'
 import { useBudgets } from '@/hooks/useBudgets'
 import { budgetItems as budgetItemsApi } from '@/lib/api'
+import { FolderOpen } from 'lucide-react'
 
 export function DashboardPage() {
   const { t } = useTranslation()
@@ -46,6 +47,29 @@ export function DashboardPage() {
     )
   }
 
+  if (list.length === 0 && !loading) {
+    return (
+      <div className="flex flex-col gap-6 p-6">
+        <div className="flex items-center gap-4">
+          <Button onClick={() => setShowCreate(true)}>{t('budget.create')}</Button>
+        </div>
+        {showCreate && (
+          <BudgetSetup
+            existingBudgets={list}
+            onCreated={handleBudgetCreated}
+            onCancel={() => setShowCreate(false)}
+          />
+        )}
+        <EmptyState
+          icon={FolderOpen}
+          heading="No budgets yet"
+          subtext="Create your first budget to start tracking your finances."
+          action={{ label: 'Create your first budget', onClick: () => setShowCreate(true) }}
+        />
+      </div>
+    )
+  }
+
   return (
     <div className="flex flex-col gap-6 p-6">
       <div className="flex items-center gap-4">
@@ -91,11 +115,11 @@ export function DashboardPage() {
           </div>
         </div>
       ) : (
-        <Card>
-          <CardContent className="py-12 text-center text-muted-foreground">
-            {t('dashboard.noBudgets')}
-          </CardContent>
-        </Card>
+        <EmptyState
+          icon={FolderOpen}
+          heading="Select a budget"
+          subtext="Select a budget to view your dashboard."
+        />
       )}
     </div>
   )