refactor: consolidate blockchain explorer into single app and update backup ignore patterns

- Remove standalone explorer-web app (README, HTML, package files)
- Add /web endpoint to blockchain-explorer for web interface access
- Update .gitignore to exclude application backup archives (*.tar.gz, *.zip)
- Add backup documentation files to .gitignore (BACKUP_INDEX.md, README.md)
- Consolidate explorer functionality into main blockchain-explorer application

apps/marketplace/src/index.css

@@ -0,0 +1,60 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+@layer base {
+  :root {
+    --background: 0 0% 100%;
+    --foreground: 222.2 84% 4.9%;
+    --card: 0 0% 100%;
+    --card-foreground: 222.2 84% 4.9%;
+    --popover: 0 0% 100%;
+    --popover-foreground: 222.2 84% 4.9%;
+    --primary: 221.2 83.2% 53.3%;
+    --primary-foreground: 210 40% 98%;
+    --secondary: 210 40% 96%;
+    --secondary-foreground: 222.2 84% 4.9%;
+    --muted: 210 40% 96%;
+    --muted-foreground: 215.4 16.3% 46.9%;
+    --accent: 210 40% 96%;
+    --accent-foreground: 222.2 84% 4.9%;
+    --destructive: 0 84.2% 60.2%;
+    --destructive-foreground: 210 40% 98%;
+    --border: 214.3 31.8% 91.4%;
+    --input: 214.3 31.8% 91.4%;
+    --ring: 221.2 83.2% 53.3%;
+    --radius: 0.5rem;
+  }
+
+  .dark {
+    --background: 222.2 84% 4.9%;
+    --foreground: 210 40% 98%;
+    --card: 222.2 84% 4.9%;
+    --card-foreground: 210 40% 98%;
+    --popover: 222.2 84% 4.9%;
+    --popover-foreground: 210 40% 98%;
+    --primary: 217.2 91.2% 59.8%;
+    --primary-foreground: 222.2 84% 4.9%;
+    --secondary: 217.2 32.6% 17.5%;
+    --secondary-foreground: 210 40% 98%;
+    --muted: 217.2 32.6% 17.5%;
+    --muted-foreground: 215 20.2% 65.1%;
+    --accent: 217.2 32.6% 17.5%;
+    --accent-foreground: 210 40% 98%;
+    --destructive: 0 62.8% 30.6%;
+    --destructive-foreground: 210 40% 98%;
+    --border: 217.2 32.6% 17.5%;
+    --input: 217.2 32.6% 17.5%;
+    --ring: 224.3 76.3% 94.1%;
+  }
+}
+
+@layer base {
+  * {
+    border-color: hsl(var(--border));
+  }
+  body {
+    background-color: hsl(var(--background));
+    color: hsl(var(--foreground));
+  }
+}