chore: remove obsolete backup directories from March 2026

- Deleted backup_20260329_183359 (block height 2222, 3 accounts, 4 transactions)
- Deleted dependency_backup_20260331_204119 (pyproject.toml, requirements files)
- Deleted pre_deployment_20260402_120429 (config examples and environment templates)

backups/pre_deployment_20260402_120838/config/python/requirements.txt

@@ -1,88 +0,0 @@
-# AITBC Central Virtual Environment Requirements
-# This file contains all Python dependencies for AITBC services
-# Merged from all subdirectory requirements files
-
-# Core Web Framework
-fastapi>=0.115.0
-uvicorn[standard]>=0.32.0
-gunicorn>=22.0.0
-
-# Database & ORM
-sqlalchemy>=2.0.0
-sqlalchemy[asyncio]>=2.0.47
-sqlmodel>=0.0.37
-alembic>=1.18.0
-aiosqlite>=0.20.0
-asyncpg>=0.29.0
-
-# Configuration & Environment
-pydantic>=2.12.0
-pydantic-settings>=2.13.0
-python-dotenv>=1.2.0
-
-# Rate Limiting & Security
-slowapi>=0.1.9
-limits>=5.8.0
-prometheus-client>=0.24.0
-
-# HTTP Client & Networking
-httpx>=0.28.0
-requests>=2.32.0
-aiohttp>=3.9.0
-
-# Cryptocurrency & Blockchain
-cryptography>=46.0.0
-pynacl>=1.5.0
-ecdsa>=0.19.0
-base58>=2.1.1
-web3>=6.11.0
-eth-account>=0.13.0
-
-# Data Processing
-pandas>=2.2.0
-numpy>=1.26.0
-
-# Development & Testing
-pytest>=8.0.0
-pytest-asyncio>=0.24.0
-black>=24.0.0
-flake8>=7.0.0
-
-# CLI Tools
-click>=8.1.0
-rich>=13.0.0
-typer>=0.12.0
-click-completion>=0.5.2
-tabulate>=0.9.0
-colorama>=0.4.4
-keyring>=23.0.0
-
-# JSON & Serialization
-orjson>=3.10.0
-msgpack>=1.1.0
-python-multipart>=0.0.6
-
-# Logging & Monitoring
-structlog>=24.1.0
-sentry-sdk>=2.0.0
-
-# Utilities
-python-dateutil>=2.9.0
-pytz>=2024.1
-schedule>=1.2.0
-aiofiles>=24.1.0
-pyyaml>=6.0
-
-# Async Support
-asyncio-mqtt>=0.16.0
-websockets>=13.0.0
-
-# Image Processing (for AI services)
-pillow>=10.0.0
-opencv-python>=4.9.0
-
-# Additional Dependencies
-redis>=5.0.0
-psutil>=5.9.0
-tenseal
-web3>=6.11.0