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>

scripts/entrypoint.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+# Tools Service Entrypoint
+# Starts both the Gateway (Axum HTTP server) and Workers (NATS consumers)
+
+set -e
+
+echo "Starting tools-gateway..."
+/app/gateway &
+GATEWAY_PID=$!
+
+sleep 1
+
+echo "Starting tools-workers..."
+/app/workers &
+WORKER_PID=$!
+
+# Handle graceful shutdown
+trap "echo 'Shutting down...'; kill $GATEWAY_PID $WORKER_PID 2>/dev/null; exit 0" SIGINT SIGTERM
+
+# Wait for either process to exit
+wait -n $GATEWAY_PID $WORKER_PID
+
+# If one exits, kill the other
+kill $GATEWAY_PID $WORKER_PID 2>/dev/null
+exit 1