Add new [W13] logo design to Warehouse13

- Replace ◆ symbol with styled [W13] logo
- Logo uses monospace font with blue border and background
- Implemented in both Angular frontend and static HTML
- Added .logo CSS class with custom styling:
  - Courier New monospace font
  - Blue (#60a5fa) color and border
  - Semi-transparent background
  - Compact bracket style representing warehouse/storage containers

The logo maintains the warehouse/storage theme while being more distinctive and modern.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/src/app/app.ts

@@ -11,7 +11,7 @@ import { ArtifactService } from './services/artifact';
   template: `
     <div class="container">
       <header>
-        <h1>◆ Warehouse13</h1>
+        <h1><span class="logo">[W13]</span> Warehouse13</h1>
         <div class="header-info">
           <span class="badge">{{ deploymentMode }}</span>
           <span class="badge">{{ storageBackend }}</span>