Improve code documentation and maintainer notes

- Add a top-level doc comment to useStreamingGeneration.ts and document the streaming lifecycle.
- Add docstrings to helper functions in useStreamingGeneration.ts.
- Add section comments to web/app/page.tsx around reducer state, server health polling, and generation handling.
- Add file-level comments to API proxy routes explaining the security architecture.
- Add a file map / maintainer guide comment to server/vibevoice_server.py.
- Add docstrings for key internal helpers in server/vibevoice_server.py.
- Document environment variables used by the server in server/vibevoice_server.py.
- Add comments identifying VibePod-specific patches around VibeVoice internals.
- Format server/vibevoice_server.py with black.

Co-authored-by: LyAhn <27559362+LyAhn@users.noreply.github.com>

web/app/api/generate/route.ts

@@ -1,3 +1,14 @@
+/**
+ * API Proxy Route: POST /api/generate
+ *
+ * This route proxies requests from the frontend to the FastAPI backend's /generate endpoint.
+ *
+ * Security Architecture:
+ * The FastAPI backend is configured to bind only to localhost (127.0.0.1). This prevents
+ * unauthenticated public access to the model inference engine. Next.js acts as a secure
+ * proxy, allowing the frontend to interact with the backend while maintaining a
+ * single public-facing origin.
+ */
 import { NextRequest, NextResponse } from "next/server";
 
 export const dynamic = "force-dynamic";

web/app/api/health/route.ts

@@ -1,3 +1,14 @@
+/**
+ * API Proxy Route: GET /api/health
+ *
+ * This route proxies health check requests from the frontend to the FastAPI backend's /health endpoint.
+ *
+ * Security Architecture:
+ * The FastAPI backend is configured to bind only to localhost (127.0.0.1). This prevents
+ * unauthenticated public access to the server status and configuration. Next.js acts as a secure
+ * proxy, allowing the frontend to poll for server readiness and adaptive configuration
+ * while maintaining a single public-facing origin.
+ */
 import { NextResponse } from "next/server";
 
 const OFFLINE_RESPONSE = { status: "offline" };