Create standalone browser port of LTX Athena with authenticated native API transport

frontend/lib/backend.ts

@@ -0,0 +1,24 @@
+let cached: { url: string; token: string } | null = null
+
+export async function getBackendCredentials(): Promise<{ url: string; token: string }> {
+  if (!cached) cached = await window.electronAPI.getBackend()
+  return cached
+}
+
+export function resetBackendCredentials(): void {
+  cached = null
+}
+
+export async function backendFetch(path: string, init?: RequestInit): Promise<Response> {
+  const { url, token } = await getBackendCredentials()
+  const headers = new Headers(init?.headers)
+  if (token) headers.set('Authorization', `Bearer ${token}`)
+  return fetch(`${url}${path}`, { ...init, headers })
+}
+
+export async function backendWsUrl(path: string): Promise<string> {
+  const { url, token } = await getBackendCredentials()
+  const ws = url.replace('http://', 'ws://')
+  const sep = path.includes('?') ? '&' : '?'
+  return `${ws}${path}${sep}token=${token}`
+}