Issue 17: StartOS 0.4.0 packaging

- Dockerfile: multi-stage build (Node frontend + Python backend)
- StartOS manifest, interfaces, backups, version graph
- start.sh: auto-generates session secret, creates first approver on boot
- Backend serves built frontend as SPA in production
- Single data volume for SQLite DB, platform backups cover it

deploy/startos/interfaces.ts

@@ -0,0 +1,24 @@
+import { sdk } from './sdk'
+
+const appPort = 8000
+
+export const setInterfaces = sdk.setupInterfaces(async ({ effects }) => {
+  const uiMulti = sdk.MultiHost.of(effects, 'ui-multi')
+  const uiMultiOrigin = await uiMulti.bindPort(appPort, {
+    protocol: 'http',
+  })
+  const ui = sdk.createInterface(effects, {
+    name: 'Web UI',
+    id: 'ui',
+    description: 'Ten31Portal fund administration interface',
+    type: 'ui',
+    masked: false,
+    schemeOverride: null,
+    username: null,
+    path: '',
+    query: {},
+  })
+
+  const uiReceipt = await uiMultiOrigin.export([ui])
+  return [uiReceipt]
+})