feat(frontend): add catch-all proxy route for ambient API v1

Add /api/ambient/v1/[...path] catch-all route that proxies requests to
the ambient-api-server backend. Supports all HTTP methods, SSE streaming,
and request body forwarding with auth header injection.

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

Author: jsell-rh

components/frontend/.env.example

@@ -12,6 +12,10 @@ GITHUB_APP_SLUG=ambient-code-vteam
 # Default local backend URL
 BACKEND_URL=http://localhost:8080/api
 
+# Ambient API Server URL (ambient-api-server microservice)
+# Proxied via /api/ambient/v1/... catch-all route
+API_SERVER_URL=http://localhost:8000
+
 # Optional: OpenShift identity details for local development
 # If you login with 'oc login', you can set these to forward identity headers
 OC_TOKEN=

components/frontend/src/app/api/ambient/v1/[...path]/route.ts

@@ -0,0 +1,84 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { buildForwardHeadersAsync } from '@/lib/auth';
+import { API_SERVER_URL } from '@/lib/config';
+
+export const runtime = 'nodejs';
+export const dynamic = 'force-dynamic';
+
+async function proxyRequest(
+  request: NextRequest,
+  { params }: { params: Promise<{ path: string[] }> },
+): Promise<Response> {
+  const { path } = await params;
+  const pathStr = path.map(s => encodeURIComponent(s)).join('/');
+  const url = new URL(`/api/ambient/v1/${pathStr}`, API_SERVER_URL);
+  url.search = request.nextUrl.search;
+
+  const headers = await buildForwardHeadersAsync(request);
+
+  // Forward content-type for requests with bodies
+  const contentType = request.headers.get('content-type');
+  if (contentType) {
+    headers['content-type'] = contentType;
+  }
+
+  let upstream: Response;
+  try {
+    upstream = await fetch(url.toString(), {
+      method: request.method,
+      headers,
+      body: request.body,
+      // @ts-expect-error -- Node.js fetch supports duplex for streaming request bodies
+      duplex: 'half',
+    });
+  } catch (error: unknown) {
+    const message = error instanceof Error ? error.message : 'Unknown error';
+    return NextResponse.json(
+      { error: 'upstream_unavailable', message },
+      { status: 502 },
+    );
+  }
+
+  // SSE/streaming: pipe through without buffering
+  const upstreamContentType = upstream.headers.get('content-type') || '';
+  if (
+    upstreamContentType.includes('text/event-stream') ||
+    upstreamContentType.includes('application/x-ndjson')
+  ) {
+    const { readable, writable } = new TransformStream();
+
+    if (upstream.body) {
+      upstream.body.pipeTo(writable).catch((err: unknown) => {
+        // AbortError is normal when client disconnects
+        if (err instanceof Error && err.name !== 'AbortError') {
+          console.error('Ambient API proxy pipe error:', err);
+        }
+      });
+    }
+
+    return new Response(readable, {
+      status: upstream.status,
+      headers: {
+        'Content-Type': upstreamContentType,
+        'Cache-Control': 'no-cache, no-store, must-revalidate',
+        Connection: 'keep-alive',
+        'X-Accel-Buffering': 'no',
+      },
+    });
+  }
+
+  // Non-streaming: buffer and forward
+  const body = await upstream.arrayBuffer();
+  return new Response(body, {
+    status: upstream.status,
+    headers: {
+      'Content-Type': upstreamContentType || 'application/json',
+    },
+  });
+}
+
+export const GET = proxyRequest;
+export const POST = proxyRequest;
+export const PUT = proxyRequest;
+export const PATCH = proxyRequest;
+export const DELETE = proxyRequest;

components/frontend/src/lib/config.ts

@@ -1,6 +1,9 @@
 // API configuration for frontend
 const BACKEND_URL = process.env.BACKEND_URL || 'http://localhost:8080/api'
 
+// Ambient API Server URL (ambient-api-server microservice)
+export const API_SERVER_URL = process.env.API_SERVER_URL || 'http://localhost:8000'
+
 /**
  * Get the API base URL for frontend requests
  */

components/frontend/src/lib/env.ts

@@ -12,6 +12,9 @@ type EnvConfig = {
   // Backend API URL (server-side only)
   BACKEND_URL: string;
 
+  // Ambient API Server URL (server-side only)
+  API_SERVER_URL: string;
+
   // GitHub configuration (public)
   GITHUB_APP_SLUG: string;
 
@@ -64,6 +67,7 @@ function getBooleanEnv(key: string, defaultValue = false): boolean {
 export const env: EnvConfig = {
   NODE_ENV: (process.env.NODE_ENV || 'development') as Environment,
   BACKEND_URL: getEnv('BACKEND_URL', 'http://localhost:8080/api'),
+  API_SERVER_URL: getEnv('API_SERVER_URL', 'http://localhost:8000'),
   GITHUB_APP_SLUG: getEnv('GITHUB_APP_SLUG', 'ambient-code-vteam'),
   FEEDBACK_URL: getOptionalEnv('FEEDBACK_URL'),
   OC_TOKEN: getOptionalEnv('OC_TOKEN'),