build: add Docker entrypoint scripts for automated setup

- Add backend entrypoint with automated Prisma migrations and client regeneration
- Add frontend entrypoint with dependency management
- Update Dockerfiles to use entrypoint scripts
- Ensures database schema stays in sync with Prisma Client after migrations

frontend/docker-entrypoint.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -e
+
+echo "🔧 Checking dependencies..."
+
+# Install dependencies if node_modules doesn't exist or package.json changed
+if [ ! -d "node_modules" ] || [ "package.json" -nt "node_modules" ]; then
+  echo "📦 Installing npm dependencies..."
+  npm install
+else
+  echo "✅ Dependencies already installed"
+fi
+
+echo "✅ Ready to start!"
+
+# Execute the main command (passed as arguments to this script)
+exec "$@"