🧪 test: implement Phase 3 parallel testing infrastructure

- Added port management system with PortManager for parallel execution
- Implemented resource monitoring with ResourceMonitor and ParallelTestRunner
- Created test-all-features-parallel.sh for parallel feature test execution
- Added comprehensive BDD_TAGS.md documentation for tag usage
- Implemented port allocation, conflict detection, and resource tracking
- Added timeout detection and controlled parallelism

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

scripts/test-all-features-parallel.sh

@@ -0,0 +1,98 @@
+#!/bin/bash
+
+# Parallel Feature Test Runner Script
+# Runs multiple feature tests in parallel with proper isolation
+
+set -e
+
+SCRIPTS_DIR=$(dirname `realpath ${BASH_SOURCE[0]}`)
+cd $SCRIPTS_DIR/..
+
+echo "🚀 Parallel Feature Test Runner"
+echo "================================"
+echo
+
+# Define features and their ports
+declare -a features=(
+    "auth:9192"
+    "config:9193"
+    "greet:9194"
+    "health:9195"
+    "jwt:9196"
+)
+
+# Function to run a single feature test
+run_feature_test() {
+    local feature_port="$1"
+    local feature_name="$2"
+    local port="$3"
+    
+    echo "🧪 Starting ${feature_name} feature tests on port ${port}..."
+    
+    # Set feature-specific environment variables
+    export DLC_DATABASE_HOST="localhost"
+    export DLC_DATABASE_PORT="5432"
+    export DLC_DATABASE_USER="postgres"
+    export DLC_DATABASE_PASSWORD="postgres"
+    export DLC_DATABASE_NAME="dance_lessons_coach_${feature_name}_test"
+    export DLC_DATABASE_SSL_MODE="disable"
+    
+    # Create feature-specific database using docker
+    if ! docker exec dance-lessons-coach-postgres psql -U postgres -lqt | cut -d \| -f 1 | grep -qw "${DLC_DATABASE_NAME}"; then
+        echo "📦 Creating ${feature_name} test database..."
+        docker exec dance-lessons-coach-postgres createdb -U postgres "${DLC_DATABASE_NAME}"
+    fi
+    
+    # Run the feature tests
+    cd "features/${feature_name}"
+    FEATURE=${feature_name} DLC_DATABASE_NAME="${DLC_DATABASE_NAME}" go test -v . 2>&1 | grep -E "(PASS|FAIL|RUN)" || true
+    
+    # Cleanup
+    cd ../..
+    docker exec dance-lessons-coach-postgres dropdb -U postgres "${DLC_DATABASE_NAME}" 2>/dev/null || true
+    
+    echo "✅ ${feature_name} feature tests completed"
+}
+
+# Check if PostgreSQL is running
+if ! docker ps --format '{{.Names}}' | grep -q "^dance-lessons-coach-postgres$"; then
+    echo "❌ PostgreSQL container is not running. Please start PostgreSQL first."
+    echo "💡 Try: docker compose up -d postgres"
+    exit 1
+fi
+
+# Check if PostgreSQL is ready
+max_attempts=10
+attempt=0
+while [ $attempt -lt $max_attempts ]; do
+    if docker exec dance-lessons-coach-postgres pg_isready -U postgres 2>/dev/null; then
+        break
+    fi
+    attempt=$((attempt + 1))
+    sleep 1
+done
+
+if [ $attempt -eq $max_attempts ]; then
+    echo "❌ PostgreSQL is not ready. Please check the container logs."
+    exit 1
+fi
+
+echo "✅ PostgreSQL is ready for parallel testing"
+echo
+
+# Run feature tests in parallel
+for feature_port in "${features[@]}"; do
+    # Split feature:port into separate variables
+    IFS=':' read -r feature_name port <<< "${feature_port}"
+    
+    # Run test in background
+    run_feature_test "${feature_port}" "${feature_name}" "${port}" &
+    
+done
+
+# Wait for all background processes to complete
+wait
+
+echo
+echo "🎉 All parallel feature tests completed!"
+echo "📊 Check individual feature test outputs above for results"