feat: initial tools service with document scanner, image & PDF tools

Self-hosted document scanner and media processing tools.
- Rust Axum gateway + worker pool with NATS JetStream
- Next.js 16 frontend with shadcn/ui
- Scanner pipeline: edge detection, warp, binarization, OCR
- Image tools: compress, resize, convert
- PDF tools: merge, split, compress
- CI/CD with Docker multi-stage build

Co-Authored-By: Kilo <kilo@kilo.ai>

frontend/src/components/tools/tool-layout.tsx

@@ -0,0 +1,47 @@
+"use client";
+
+import type { LucideIcon } from "lucide-react";
+
+interface ToolLayoutProps {
+  title: string;
+  description: string;
+  icon: LucideIcon;
+  phase: number;
+  children: React.ReactNode;
+}
+
+export function ToolLayout({
+  title,
+  description,
+  icon: Icon,
+  phase,
+  children,
+}: ToolLayoutProps) {
+  const isAvailable = phase === 1;
+
+  return (
+    <div className="container mx-auto px-4 py-8 max-w-3xl">
+      <div className="flex items-center gap-3 mb-8">
+        <div className="p-2 rounded-lg bg-primary/10 text-primary">
+          <Icon className="h-6 w-6" />
+        </div>
+        <div>
+          <h1 className="text-2xl font-bold">{title}</h1>
+          <p className="text-sm text-muted-foreground">{description}</p>
+        </div>
+      </div>
+
+      {!isAvailable ? (
+        <div className="p-8 rounded-xl border glass text-center space-y-3">
+          <p className="text-lg font-medium">Coming Soon</p>
+          <p className="text-sm text-muted-foreground">
+            Tool ini sedang dalam pengembangan dan akan tersedia di fase
+            berikutnya.
+          </p>
+        </div>
+      ) : (
+        children
+      )}
+    </div>
+  );
+}