feat: add devcontainer configuration and setup script

.devcontainer/start.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+set -e
+
+echo "Starting devcontainer setup..."
+
+echo "Installing dependencies..."
+# install dependencies
+pnpm install --frozen-lockfile
+cargo install sea-orm-cli
+
+echo "building agent image..."
+# build agent image
+cd apps/agent
+just build-docker
+cd -
+echo "Agent image built."
+
+echo "Devcontainer setup complete."