ux: P0 fixes from UI audit — affordance, IA consolidation, showcase icons

P0 #1 — Homepage subhead linked 'Free, open source.' to /vs-books which
was a misleading affordance (users expect a definition page, got a
comparison). Now links 'open source on GitHub' to the actual repo. Same
fix on mobile copy.

P0 #2 — /generator and /toolbox were competing for the same intent (two
clicks to reach the form). Embedded GeneratorClient inline at the top
of /toolbox under #generators. /generator route remains for deep-links
but canonical now points to /toolbox. Homepage CTA updated to
/toolbox#generators.

P1 #3 — /built-with cards were text-only. Added favicons via Google's
service (CSP-allowed), reorganized card header with icon + name +
surface badges (🌐 🍎 🤖) + stack, Visit → on the right.

Verified locally with `next build` — all routes prerender cleanly.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: dotsystemsdevs

src/app/generator/page.tsx

@@ -8,7 +8,7 @@ export const metadata: Metadata = {
   title: "AGENTS.md & PRD Generator — fill in, get ready-to-ship markdown | vibeprompt",
   description:
     "Free AGENTS.md and PRD generator for vibe coders. Fill in your project details, get production-ready markdown to drop into your repo. No sign-up, no API key, runs in your browser.",
-  alternates: { canonical: "/generator" },
+  alternates: { canonical: "/toolbox" },
   keywords:
     "AGENTS.md generator, PRD generator, CLAUDE.md generator, vibe coding generator, AI context file, Claude Code setup, Cursor setup, AGENTS.md template",
   openGraph: {