Initial commit: investment dashboard with contributions panel and forecast chart

React + Vite frontend with a local-JSON-backed API (Vite middleware) for
tracking portfolio holdings, contributions/withdrawals, recurring
contribution plans, and a forecast chart comparing the portfolio's real
value against a same-contributions S&P 500 benchmark.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

vite.config.ts

@@ -0,0 +1,8 @@
+import react from '@vitejs/plugin-react'
+import { defineConfig } from 'vite'
+import { apiPlugin } from './server/apiPlugin.ts'
+
+// https://vite.dev/config/
+export default defineConfig({
+  plugins: [react(), apiPlugin()],
+})