feat: add Docker support with PostgreSQL and health check endpoint

scripts/init-postgres.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -e
+
+# This script runs when the PostgreSQL container is first initialized
+# It creates the shadow database for Prisma migrations
+
+psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --dbname "$POSTGRES_DB" <<-EOSQL
+    -- Create shadow database for Prisma migrations
+    CREATE DATABASE "euchre_camp_shadow";
+    
+    -- Grant privileges
+    GRANT ALL PRIVILEGES ON DATABASE "euchre_camp_shadow" TO "$POSTGRES_USER";
+EOSQL
+
+echo "PostgreSQL initialization completed"