Restructure Web App into server/ + web/ (GsmNode parity)

Reorganize the Web App to match the GsmNode project layout: a Go
backend-for-frontend in server/ that embeds the built SPA and reverse-proxies
/api/* to the API Server, with the Vue 3 + Vite frontend moved into web/.

- Move all frontend files into web/ (history preserved via renames)
- Point vite build output at ../server/dist for Go embedding
- Add server/ Go BFF (main.go, go.mod, .env.example, Run-WebApp.ps1)
- Drop Docker/nginx deploy (Dockerfile, docker-compose.yml, nginx.conf.template,
  .dockerignore) in favor of the BFF, matching GsmNode
- Update .claude/launch.json to run the dev server from web/
- Rewrite README.md for the new layout

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Web App/web/vite.config.js

@@ -0,0 +1,29 @@
+import { defineConfig } from "vite";
+import vue from "@vitejs/plugin-vue";
+import tailwindcss from "@tailwindcss/vite";
+
+// The web app talks ONLY to the API Server. The production build is written into
+// ../server/dist so the Go BFF can embed it. In dev, /api is proxied to the API
+// Server so we avoid CORS and can use same-origin relative URLs in the client.
+export default defineConfig({
+  plugins: [vue(), tailwindcss()],
+  build: {
+    outDir: "../server/dist",
+    emptyOutDir: true,
+  },
+  server: {
+    port: 5173,
+    // Listen on all interfaces so the dev server is reachable on the LAN
+    // (e.g. http://10.2.1.101:5173 from another device).
+    host: true,
+    // Allow access via the LAN hostname/IP (Vite's host check otherwise blocks
+    // non-localhost Host headers). true = accept any host (fine for LAN dev).
+    allowedHosts: true,
+    proxy: {
+      "/api": {
+        target: process.env.VITE_API_TARGET || "http://localhost:8080",
+        changeOrigin: true,
+      },
+    },
+  },
+});