feat: initial scaffold - backend, frontend, Prisma schema, Docker

- Prisma schema: User, Session, RepoConfig, Preview, Job, WebhookToken, NoConfigComment, AdminSettings
- Backend: auth (login/logout/me/first-user setup), webhook handler with HMAC verification, EC2 service, SSH service, deploy pipeline, job queue worker, cron workers
- Frontend: Login with first-user detection, Dashboard, PreviewDetail with live log streaming, Settings, Repos config, Admin panel, SetupWizard, Privacy page
- Docker Compose and Dockerfile for self-hosted deployment
- Uses bcryptjs for Node 24 compatibility

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

frontend/vite.config.ts

@@ -0,0 +1,16 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+
+export default defineConfig({
+  plugins: [react()],
+  server: {
+    port: 3000,
+    proxy: {
+      "/api": "http://localhost:5000",
+      "/webhook": "http://localhost:5000",
+    },
+  },
+  build: {
+    outDir: "dist",
+  },
+});