fix: forward browser Host via Vite proxy for correct API docs URLs

Vite proxy now sends X-Forwarded-Host and X-Forwarded-Proto headers
to the backend, so /openapi.json and /docs show the actual browser
address (e.g. http://192.168.1.28:5173) instead of localhost:8000.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/vite.config.ts

@@ -3,6 +3,21 @@ import react from '@vitejs/plugin-react'
 import tailwindcss from '@tailwindcss/vite'
 import path from 'path'
 
+// Forward browser's original Host to the backend so API docs URLs match
+function forwardHost() {
+  return {
+    configure: (proxy: any) => {
+      proxy.on('proxyReq', (proxyReq: any, req: any) => {
+        const host = req.headers.host;
+        if (host) {
+          proxyReq.setHeader('X-Forwarded-Host', host);
+          proxyReq.setHeader('X-Forwarded-Proto', 'http');
+        }
+      });
+    },
+  };
+}
+
 export default defineConfig({
   plugins: [react(), tailwindcss()],
   resolve: {
@@ -12,10 +27,10 @@ export default defineConfig({
   },
   server: {
     proxy: {
-      '/api': 'http://localhost:8000',
-      '/docs': 'http://localhost:8000',
-      '/redoc': 'http://localhost:8000',
-      '/openapi.json': 'http://localhost:8000',
+      '/api': { target: 'http://localhost:8000', ...forwardHost() },
+      '/docs': { target: 'http://localhost:8000', ...forwardHost() },
+      '/redoc': { target: 'http://localhost:8000', ...forwardHost() },
+      '/openapi.json': { target: 'http://localhost:8000', ...forwardHost() },
     },
   },
 })