feat: add complete Docker setup for testing

- Update docker-compose.yml with frontend service and healthchecks

- Add frontend Dockerfile with dev and production stages

- Add nginx.conf for production frontend serving

- Add docker-compose.prod.yml for production deployment

- Add .env.example with all configuration options

- Add init scripts (init.sh, init.ps1) for easy setup

.env.example

@@ -0,0 +1,24 @@
+# =============================================================================
+# Aegis Environment Variables
+# =============================================================================
+# Copy this file to .env and fill in the values
+# =============================================================================
+
+# ── Database ─────────────────────────────────────────────────────────────────
+DB_USER=postgres
+DB_PASSWORD=change-me-in-production
+DB_NAME=attackdb
+
+# ── Security ─────────────────────────────────────────────────────────────────
+# IMPORTANT: Generate a strong random key for production
+# Example: openssl rand -hex 32
+SECRET_KEY=change-me-in-production-use-a-long-random-string
+TOKEN_EXPIRE_MINUTES=60
+
+# ── MinIO Object Storage ─────────────────────────────────────────────────────
+MINIO_ACCESS_KEY=minioadmin
+MINIO_SECRET_KEY=change-me-in-production
+MINIO_BUCKET=evidence
+
+# ── Frontend ─────────────────────────────────────────────────────────────────
+FRONTEND_PORT=80