feat: use waveform banner as website header logo

- Remove banner from welcome page content
- Update header logo to use banner-bmad-method2.png

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/index.md

@@ -2,8 +2,6 @@
 title: Welcome to the BMad Method
 ---
 
-![BMad Method](/img/banner-bmad-method2.png)
-
 The BMad Method (**B**reakthrough **M**ethod of **A**gile AI **D**riven Development) is an AI-driven development framework that helps you build software faster and smarter. It provides specialized AI agents, guided workflows, and intelligent planning that adapts to your project's complexity—whether you're fixing a bug or building an enterprise platform.
 
 If you're comfortable working with AI coding assistants like Claude, Cursor, or GitHub Copilot, you're ready to get started.

website/astro.config.mjs

@@ -38,7 +38,7 @@ export default defineConfig({
       tagline: 'AI-driven agile development with specialized agents and workflows that scale from bug fixes to enterprise platforms.',
 
       logo: {
-        src: './public/img/bmad-wordmark.png',
+        src: './public/img/banner-bmad-method2.png',
         alt: 'BMAD Method',
         replacesTitle: true,
       },