feat: initial finance SPA — phases 1 & 2

Next.js 16 personal finance dashboard connected to postgres-personal.

Phase 1 (Foundation):
- API routes: GET /api/transactions (paginated, filterable, sortable),
  GET /api/statements, GET /api/merchants
- Transactions data table with date/category/bank/search filters, pagination, sort
- Statements card grid with period, due date, amount, transaction count
- Sidebar layout with nav for all planned sections

Phase 2 (Normalisation):
- PATCH /api/transactions/[id] — upsert transaction_overrides
- POST /api/transactions/bulk — bulk categorize/normalize
- Inline click-to-edit category (22 options) and merchant name
- Blue dot override indicator, bulk action bar
- Effective values via COALESCE(override, llm_value) pattern

Stack: Next.js 16 (App Router, standalone), Prisma 7.x + @prisma/adapter-pg,
TanStack Query, Tailwind CSS. Auth via Traefik chain-oauth@file.

src/app/api/merchants/route.ts

@@ -0,0 +1,16 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getMerchantSuggestions, getBankNames } from "@/lib/queries";
+
+export async function GET(req: NextRequest) {
+  const search = req.nextUrl.searchParams.get("search");
+  const type = req.nextUrl.searchParams.get("type");
+
+  if (type === "banks") {
+    const banks = await getBankNames();
+    return NextResponse.json(banks.map((b) => b.bank_name));
+  }
+
+  if (!search) return NextResponse.json([]);
+  const merchants = await getMerchantSuggestions(search);
+  return NextResponse.json(merchants.map((m) => m.merchant));
+}

src/app/api/statements/[id]/route.ts

@@ -0,0 +1,12 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getStatementById } from "@/lib/queries";
+
+export async function GET(
+  _req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const { id } = await params;
+  const stmt = await getStatementById(Number(id));
+  if (!stmt) return NextResponse.json({ error: "Not found" }, { status: 404 });
+  return NextResponse.json(stmt);
+}

src/app/api/statements/route.ts

@@ -0,0 +1,7 @@
+import { NextResponse } from "next/server";
+import { getStatements } from "@/lib/queries";
+
+export async function GET() {
+  const statements = await getStatements();
+  return NextResponse.json(statements);
+}

src/app/api/transactions/[id]/route.ts

@@ -0,0 +1,46 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getTransactionById } from "@/lib/queries";
+import { prisma } from "@/lib/db";
+
+export async function GET(
+  _req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const { id } = await params;
+  const txn = await getTransactionById(Number(id));
+  if (!txn) return NextResponse.json({ error: "Not found" }, { status: 404 });
+  return NextResponse.json(txn);
+}
+
+export async function PATCH(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const { id } = await params;
+  const transactionId = Number(id);
+  const body = await req.json();
+
+  const { category, merchant_normalized, notes } = body as {
+    category?: string;
+    merchant_normalized?: string;
+    notes?: string;
+  };
+
+  const data: Record<string, unknown> = { updated_at: new Date() };
+  if (category !== undefined) data.category_override = category;
+  if (merchant_normalized !== undefined) data.merchant_normalized = merchant_normalized;
+  if (notes !== undefined) data.notes = notes;
+
+  const override = await prisma.transaction_overrides.upsert({
+    where: { transaction_id: transactionId },
+    update: data,
+    create: {
+      transaction_id: transactionId,
+      category_override: category || null,
+      merchant_normalized: merchant_normalized || null,
+      notes: notes || null,
+    },
+  });
+
+  return NextResponse.json(override);
+}

src/app/api/transactions/bulk/route.ts

@@ -0,0 +1,42 @@
+import { NextRequest, NextResponse } from "next/server";
+import { prisma } from "@/lib/db";
+
+export async function POST(req: NextRequest) {
+  const body = await req.json();
+  const { action, ids, category, merchant_normalized } = body as {
+    action: string;
+    ids: number[];
+    category?: string;
+    merchant_normalized?: string;
+  };
+
+  if (!ids || !Array.isArray(ids) || ids.length === 0) {
+    return NextResponse.json({ error: "ids required" }, { status: 400 });
+  }
+
+  if (action === "categorize" && category) {
+    const ops = ids.map((id) =>
+      prisma.transaction_overrides.upsert({
+        where: { transaction_id: id },
+        update: { category_override: category, updated_at: new Date() },
+        create: { transaction_id: id, category_override: category },
+      })
+    );
+    await prisma.$transaction(ops);
+    return NextResponse.json({ updated: ids.length });
+  }
+
+  if (action === "normalize" && merchant_normalized) {
+    const ops = ids.map((id) =>
+      prisma.transaction_overrides.upsert({
+        where: { transaction_id: id },
+        update: { merchant_normalized, updated_at: new Date() },
+        create: { transaction_id: id, merchant_normalized },
+      })
+    );
+    await prisma.$transaction(ops);
+    return NextResponse.json({ updated: ids.length });
+  }
+
+  return NextResponse.json({ error: "Invalid action" }, { status: 400 });
+}

src/app/api/transactions/route.ts

@@ -0,0 +1,21 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getTransactions } from "@/lib/queries";
+
+export async function GET(req: NextRequest) {
+  const sp = req.nextUrl.searchParams;
+
+  const result = await getTransactions({
+    from: sp.get("from") || undefined,
+    to: sp.get("to") || undefined,
+    category: sp.get("category") || undefined,
+    bank_name: sp.get("bank_name") || undefined,
+    search: sp.get("search") || undefined,
+    statement_id: sp.get("statement_id") || undefined,
+    sort_by: sp.get("sort_by") || undefined,
+    sort_dir: sp.get("sort_dir") || undefined,
+    limit: sp.get("limit") ? Number(sp.get("limit")) : undefined,
+    offset: sp.get("offset") ? Number(sp.get("offset")) : undefined,
+  });
+
+  return NextResponse.json(result);
+}