feat: Phase 0 - Infrastructure and scaffolding (T-001 to T-003)

This commit establishes the foundational infrastructure for the Aegis
MITRE ATT&CK Coverage Platform.

T-001: Initialize project and Docker Compose
- Set up Docker Compose with PostgreSQL 15, MinIO, and FastAPI backend
- Create basic FastAPI application with health endpoint
- Configure persistent volumes for data storage

T-002: Configuration and database connection
- Add centralized configuration using pydantic-settings
- Implement SQLAlchemy database connection with session management
- Configure MinIO and JWT settings

T-003: Initialize Alembic for migrations
- Set up Alembic with PostgreSQL connection from settings
- Create initial empty migration
- Configure autogenerate support for future models

Also includes:
- Professional README with setup instructions
- Comprehensive .gitignore for Python/Node/Docker
- Project task plan (AegisTestPlan.md)

backend/requirements.txt

@@ -0,0 +1,13 @@
+fastapi
+uvicorn[standard]
+sqlalchemy
+psycopg2-binary
+alembic
+python-jose[cryptography]
+passlib[bcrypt]
+boto3
+apscheduler
+requests
+taxii2-client
+python-multipart
+pydantic-settings