Add paycheck tracking workflow for v1

src/app/income/page.tsx

@@ -1,15 +1,21 @@
+import { PaycheckWorkspace } from "@/components/paycheck-workspace";
+
 export const metadata = {
   title: "Income & Paychecks | Monthy Tracker",
 };
 
 export default function IncomePage() {
   return (
-    <div className="rounded-[2rem] border border-stone-200 bg-white p-8 shadow-[0_24px_60px_rgba(120,90,50,0.08)]">
-      <p className="text-sm font-semibold uppercase tracking-[0.28em] text-stone-500">Coming next</p>
-      <h1 className="mt-3 text-4xl font-semibold text-stone-950">Paycheck tracking lands in the next implementation slice.</h1>
-      <p className="mt-4 max-w-2xl text-lg leading-8 text-stone-600">
-        The data model is already prepared for paychecks. This view will add create, list, and delete flows after expense tracking is validated.
-      </p>
+    <div className="space-y-8">
+      <header className="max-w-2xl space-y-3">
+        <p className="text-sm font-semibold uppercase tracking-[0.28em] text-emerald-700">Income & Paychecks</p>
+        <h1 className="text-4xl font-semibold text-stone-950">Capture income on real pay dates, not rough monthly averages.</h1>
+        <p className="text-lg leading-8 text-stone-600">
+          This slice tracks each paycheck as a distinct event so later dashboard and AI guidance can reason about cash timing accurately.
+        </p>
+      </header>
+
+      <PaycheckWorkspace />
     </div>
   );
 }

src/app/paychecks/[id]/route.ts

@@ -0,0 +1,23 @@
+import { Prisma } from "@prisma/client";
+import { NextResponse } from "next/server";
+
+import { removePaycheck } from "@/lib/paychecks";
+
+type RouteContext = {
+  params: Promise<{ id: string }>;
+};
+
+export async function DELETE(_: Request, context: RouteContext) {
+  const { id } = await context.params;
+
+  try {
+    await removePaycheck(id);
+    return new NextResponse(null, { status: 204 });
+  } catch (error) {
+    if (error instanceof Prisma.PrismaClientKnownRequestError && error.code === "P2025") {
+      return NextResponse.json({ error: "Paycheck not found." }, { status: 404 });
+    }
+
+    throw error;
+  }
+}

src/app/paychecks/route.ts

@@ -0,0 +1,28 @@
+import { NextResponse } from "next/server";
+
+import { createPaycheck, listPaychecks } from "@/lib/paychecks";
+import { paycheckInputSchema } from "@/lib/validation";
+
+export async function GET() {
+  const paychecks = await listPaychecks();
+  return NextResponse.json({ paychecks });
+}
+
+export async function POST(request: Request) {
+  const payload = await request.json();
+  const parsed = paycheckInputSchema.safeParse(payload);
+
+  if (!parsed.success) {
+    return NextResponse.json(
+      { error: parsed.error.issues[0]?.message ?? "Invalid paycheck payload." },
+      { status: 400 },
+    );
+  }
+
+  const paycheck = await createPaycheck({
+    amountCents: parsed.data.amount,
+    payDate: parsed.data.payDate,
+  });
+
+  return NextResponse.json({ paycheck }, { status: 201 });
+}