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/components/ui/progress.tsx

@@ -0,0 +1,26 @@
+import * as React from "react"
+import * as ProgressPrimitive from "@radix-ui/react-progress"
+
+import { cn } from "@/lib/utils"
+
+const Progress = React.forwardRef<
+  React.ElementRef<typeof ProgressPrimitive.Root>,
+  React.ComponentPropsWithoutRef<typeof ProgressPrimitive.Root>
+>(({ className, value, ...props }, ref) => (
+  <ProgressPrimitive.Root
+    ref={ref}
+    className={cn(
+      "relative h-4 w-full overflow-hidden rounded-full bg-secondary",
+      className
+    )}
+    {...props}
+  >
+    <ProgressPrimitive.Indicator
+      className="h-full w-full flex-1 bg-primary transition-all"
+      style={{ transform: `translateX(-${100 - (value || 0)}%)` }}
+    />
+  </ProgressPrimitive.Root>
+))
+Progress.displayName = ProgressPrimitive.Root.displayName
+
+export { Progress }