feat(lab-04): complete Phase 5 - Storage & S3 lab

Phase Plan:
- 05-PLAN.md: Combined execution plan for efficiency
- 05-RESEARCH.md: Domain research on volumes and MinIO

Test Scripts (4):
- 01-volumes-test.sh: Volume persistence verification
- 02-minio-test.sh: MinIO S3 API testing
- 03-persistence-test.sh: Database persistence verification
- 99-final-verification.sh: End-to-end verification

Documentation (6 files):
Tutorial: Docker volumes, MinIO S3
How-to: Manage volumes
Reference: Volume syntax
Explanation: Storage↔S3 parallels

Infrastructure:
- docker-compose.yml: MinIO S3 + PostgreSQL + test container
- Named volumes: minio-data, db-data, test-data (INF-04 compliant)

Key concepts:
- Named volumes = EBS volumes
- MinIO = S3 bucket (100% API compatible)
- Data persistence across container lifecycle

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

labs/lab-04-storage/tests/01-volumes-test.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+# Test Docker Volumes persistence
+echo "Testing Docker Volumes..."
+docker compose up -d test && sleep 2
+docker exec lab04-test sh -c "echo 'data' > /test/persistent.txt"
+docker compose down
+docker compose up -d test && sleep 2
+if docker exec lab04-test cat /test/persistent.txt | grep -q "data"; then
+    echo "✓ Volume persistence works"
+    exit 0
+else
+    echo "✗ Volume persistence failed"
+    exit 1
+fi

labs/lab-04-storage/tests/02-minio-test.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+# Test MinIO S3 API
+echo "Testing MinIO S3 API..."
+docker compose up -d minio && sleep 5
+# Wait for MinIO to be ready
+for i in {1..10}; do
+    if curl -sf http://127.0.0.1:9000/minio/health/live &>/dev/null; then
+        echo "✓ MinIO is ready"
+        break
+    fi
+    sleep 2
+done
+# Test S3 API with mc (MinIO client)
+docker exec lab04-minio mc alias set local http://localhost:9000 minioadmin minioadmin123
+docker exec lab04-minio mc mb local/testbucket
+if docker exec lab04-minio mc ls local/ | grep -q "testbucket"; then
+    echo "✓ S3 bucket creation works"
+    exit 0
+else
+    echo "✗ S3 bucket creation failed"
+    exit 1
+fi

labs/lab-04-storage/tests/03-persistence-test.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test data persistence in database
+echo "Testing database persistence..."
+docker compose up -d db && sleep 10
+docker exec lab04-db psql -U lab04_user -d lab04_db -c "CREATE TABLE IF NOT EXISTS test (id SERIAL, data TEXT);"
+docker exec lab04-db psql -U lab04_user -d lab04_db -c "INSERT INTO test (data) VALUES ('persistent');"
+docker compose down
+docker compose up -d db && sleep 10
+RESULT=$(docker exec lab04-db psql -U lab04_user -d lab04_db -tAc "SELECT data FROM test WHERE id=1;")
+if [[ "$RESULT" == "persistent" ]]; then
+    echo "✓ Database persistence works"
+    exit 0
+else
+    echo "✗ Database persistence failed"
+    exit 1
+fi

labs/lab-04-storage/tests/99-final-verification.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+# Final verification for Lab 04
+echo "Lab 04 Final Verification"
+cd "$(dirname "$0")/.."
+pass=0; fail=0
+check() { if eval "$1"; then echo "✓ $2"; ((pass++)); else echo "✗ $2"; ((fail++)); fi; }
+
+# Infrastructure checks
+check "[[ -f docker-compose.yml ]]" "docker-compose.yml exists"
+check "docker compose config &>/dev/null" "Syntax valid"
+
+# Start services
+docker compose up -d && sleep 8
+
+# Volume checks
+VOLUMES=$(docker volume ls --format '{{.Name}}' | grep -c "lab04" || echo "0")
+check "[[ $VOLUMES -ge 3 ]]" "Named volumes created ($VOLUMES)"
+
+# MinIO checks
+check "curl -sf http://127.0.0.1:9000/minio/health/live" "MinIO API accessible"
+check "curl -sf http://127.0.0.1:9001 &>/dev/null" "MinIO console accessible"
+
+# Persistence check
+docker exec lab04-test sh -c "echo test > /test/file.txt"
+docker compose restart test && sleep 3
+check "docker exec lab04-test cat /test/file.txt | grep -q test" "Data persists after restart"
+
+echo "Passed: $pass, Failed: $fail"
+[[ $fail -eq 0 ]] && exit 0 || exit 1