feat: category import from CSV + budget auto-assign rules

Category:
- Add categoryColumn to NormalizerConfig and NormalizedRow
- Map 'Category' column for Discover CC profile
- Write category to Transaction on upload

Budget rules:
- Add BudgetRule model (userId, budgetId, pattern)
- API: GET/POST /api/budget-rules, DELETE /api/budget-rules/:id
- Apply rules during upload (first case-insensitive match wins)
- Budgets page fetches and passes rules per budget
- BudgetCard 'Rules' menu item opens BudgetRulesDialog for add/delete

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/budgets/BudgetCard.tsx

@@ -7,11 +7,17 @@ import {
   DropdownMenu, DropdownMenuContent, DropdownMenuItem, DropdownMenuSeparator,
   DropdownMenuTrigger,
 } from '@/components/ui/dropdown-menu'
-import { MoreHorizontal, Pencil, Trash2, EyeOff, Eye } from 'lucide-react'
+import { MoreHorizontal, Pencil, Trash2, EyeOff, Eye, ListFilter } from 'lucide-react'
 import { BudgetProgress } from './BudgetProgress'
 import { CreateBudgetDialog } from './CreateBudgetDialog'
+import { BudgetRulesDialog } from './BudgetRulesDialog'
 import { formatCents } from '@/lib/utils/currency'
 
+export interface BudgetRule {
+  id: string
+  pattern: string
+}
+
 export interface BudgetWithSpend {
   id: string
   name: string
@@ -19,11 +25,13 @@ export interface BudgetWithSpend {
   color: string | null
   isActive: boolean
   spendCents: number
+  rules?: BudgetRule[]
 }
 
 export function BudgetCard({ budget }: { budget: BudgetWithSpend }) {
   const router = useRouter()
   const [editOpen, setEditOpen] = useState(false)
+  const [rulesOpen, setRulesOpen] = useState(false)
 
   async function handleToggle() {
     await fetch(`/api/budgets/${budget.id}`, {
@@ -62,6 +70,9 @@ export function BudgetCard({ budget }: { budget: BudgetWithSpend }) {
               <DropdownMenuItem onClick={() => setEditOpen(true)}>
                 <Pencil className="h-4 w-4 mr-2" />Edit
               </DropdownMenuItem>
+              <DropdownMenuItem onClick={() => setRulesOpen(true)}>
+                <ListFilter className="h-4 w-4 mr-2" />Rules
+              </DropdownMenuItem>
               <DropdownMenuItem onClick={handleToggle}>
                 {budget.isActive
                   ? <><EyeOff className="h-4 w-4 mr-2" />Deactivate</>
@@ -102,6 +113,13 @@ export function BudgetCard({ budget }: { budget: BudgetWithSpend }) {
       </Card>
 
       <CreateBudgetDialog open={editOpen} onOpenChange={setEditOpen} budget={budget} />
+      <BudgetRulesDialog
+        open={rulesOpen}
+        onOpenChange={setRulesOpen}
+        budgetId={budget.id}
+        budgetName={budget.name}
+        rules={budget.rules ?? []}
+      />
     </>
   )
 }

src/components/budgets/BudgetRulesDialog.tsx

@@ -0,0 +1,96 @@
+'use client'
+
+import { useState } from 'react'
+import { useRouter } from 'next/navigation'
+import { Dialog, DialogContent, DialogHeader, DialogTitle } from '@/components/ui/dialog'
+import { Button } from '@/components/ui/button'
+import { Input } from '@/components/ui/input'
+import { Trash2, Plus } from 'lucide-react'
+
+interface Rule {
+  id: string
+  pattern: string
+}
+
+interface Props {
+  open: boolean
+  onOpenChange: (open: boolean) => void
+  budgetId: string
+  budgetName: string
+  rules: Rule[]
+}
+
+export function BudgetRulesDialog({ open, onOpenChange, budgetId, budgetName, rules }: Props) {
+  const router = useRouter()
+  const [pattern, setPattern] = useState('')
+  const [adding, setAdding] = useState(false)
+
+  async function handleAdd(e: React.FormEvent) {
+    e.preventDefault()
+    if (!pattern.trim()) return
+    setAdding(true)
+    await fetch('/api/budget-rules', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ budgetId, pattern: pattern.trim() }),
+    })
+    setPattern('')
+    setAdding(false)
+    router.refresh()
+  }
+
+  async function handleDelete(id: string) {
+    await fetch(`/api/budget-rules/${id}`, { method: 'DELETE' })
+    router.refresh()
+  }
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent className="max-w-md">
+        <DialogHeader>
+          <DialogTitle>Auto-assign rules — {budgetName}</DialogTitle>
+        </DialogHeader>
+
+        <p className="text-sm text-muted-foreground">
+          Transactions whose description contains a pattern (case-insensitive) are automatically
+          assigned to this budget on upload. First matching rule wins.
+        </p>
+
+        {rules.length === 0 ? (
+          <p className="text-sm text-muted-foreground text-center py-2">No rules yet.</p>
+        ) : (
+          <ul className="space-y-1.5">
+            {rules.map((rule) => (
+              <li
+                key={rule.id}
+                className="flex items-center justify-between gap-2 rounded-md border px-3 py-2 text-sm"
+              >
+                <span className="font-mono truncate">{rule.pattern}</span>
+                <button
+                  onClick={() => handleDelete(rule.id)}
+                  className="shrink-0 text-muted-foreground hover:text-destructive transition-colors"
+                  aria-label="Delete rule"
+                >
+                  <Trash2 className="h-3.5 w-3.5" />
+                </button>
+              </li>
+            ))}
+          </ul>
+        )}
+
+        <form onSubmit={handleAdd} className="flex gap-2">
+          <Input
+            placeholder="e.g. Amazon, Netflix, Starbucks"
+            value={pattern}
+            onChange={(e) => setPattern(e.target.value)}
+            className="flex-1"
+          />
+          <Button type="submit" disabled={adding || !pattern.trim()} size="sm">
+            <Plus className="h-4 w-4 mr-1" />
+            Add
+          </Button>
+        </form>
+      </DialogContent>
+    </Dialog>
+  )
+}