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/app/api/budget-rules/[id]/route.ts

@@ -0,0 +1,16 @@
+import { NextResponse } from 'next/server'
+import { auth } from '@/lib/auth'
+import { prisma } from '@/lib/prisma'
+
+export async function DELETE(_req: Request, { params }: { params: Promise<{ id: string }> }) {
+  const session = await auth()
+  if (!session?.user?.id) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+
+  const { id } = await params
+
+  const rule = await prisma.budgetRule.findFirst({ where: { id, userId: session.user.id } })
+  if (!rule) return NextResponse.json({ error: 'Not found' }, { status: 404 })
+
+  await prisma.budgetRule.delete({ where: { id } })
+  return new NextResponse(null, { status: 204 })
+}

src/app/api/budget-rules/route.ts

@@ -0,0 +1,37 @@
+import { NextResponse } from 'next/server'
+import { auth } from '@/lib/auth'
+import { prisma } from '@/lib/prisma'
+import { createBudgetRuleSchema } from '@/lib/validations/budget-rule'
+
+export async function GET() {
+  const session = await auth()
+  if (!session?.user?.id) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+
+  const rules = await prisma.budgetRule.findMany({
+    where: { userId: session.user.id },
+    orderBy: { createdAt: 'asc' },
+    select: { id: true, budgetId: true, pattern: true },
+  })
+  return NextResponse.json(rules)
+}
+
+export async function POST(req: Request) {
+  const session = await auth()
+  if (!session?.user?.id) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+
+  const body = await req.json()
+  const parsed = createBudgetRuleSchema.safeParse(body)
+  if (!parsed.success) return NextResponse.json({ error: parsed.error.flatten() }, { status: 400 })
+
+  const { budgetId, pattern } = parsed.data
+
+  // Verify budget belongs to this user
+  const budget = await prisma.budget.findFirst({ where: { id: budgetId, userId: session.user.id } })
+  if (!budget) return NextResponse.json({ error: 'Budget not found' }, { status: 404 })
+
+  const rule = await prisma.budgetRule.create({
+    data: { userId: session.user.id, budgetId, pattern },
+    select: { id: true, budgetId: true, pattern: true },
+  })
+  return NextResponse.json(rule, { status: 201 })
+}

src/app/api/upload/route.ts

@@ -76,6 +76,22 @@ export async function POST(req: Request) {
 
   const normalized = normalizeRows(allRows, accountId, config)
 
+  // Apply budget auto-assign rules (first match wins)
+  const budgetRules = await prisma.budgetRule.findMany({
+    where: { userId: session.user.id },
+    orderBy: { createdAt: 'asc' },
+    select: { pattern: true, budgetId: true },
+  })
+  const rowsWithBudgets = normalized.map((row) => {
+    const desc = row.description.toLowerCase()
+    for (const rule of budgetRules) {
+      if (desc.includes(rule.pattern.toLowerCase())) {
+        return { ...row, budgetId: rule.budgetId }
+      }
+    }
+    return { ...row, budgetId: null }
+  })
+
   const upload = await prisma.csvUpload.create({
     data: {
       accountId,
@@ -89,13 +105,15 @@ export async function POST(req: Request) {
 
   try {
     const { count: importedCount } = await prisma.transaction.createMany({
-      data: normalized.map((r) => ({
+      data: rowsWithBudgets.map((r) => ({
         accountId,
         uploadId: upload.id,
         date: r.date,
         description: r.description,
         amountCents: r.amountCents,
         type: r.type,
+        category: r.category ?? null,
+        budgetId: r.budgetId,
         dedupeHash: r.dedupeHash,
       })),
       skipDuplicates: true,
@@ -118,7 +136,7 @@ export async function POST(req: Request) {
     // Upsert balance snapshots for each affected month
     const months = [
       ...new Map(
-        normalized.map((r) => {
+        rowsWithBudgets.map((r) => {
           const y = r.date.getFullYear()
           const m = r.date.getMonth() + 1
           return [`${y}-${m}`, { year: y, month: m }]