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_120429/config/.env.example

@@ -1,58 +0,0 @@
-# AITBC Central Environment Example Template
-# SECURITY NOTICE: Use a secrets manager for production. Do not commit real secrets.
-# Run: python config/security/environment-audit.py --format text
-
-# =========================
-# Blockchain core
-# =========================
-chain_id=ait-mainnet
-supported_chains=ait-mainnet
-rpc_bind_host=0.0.0.0
-rpc_bind_port=8006
-p2p_bind_host=0.0.0.0
-p2p_bind_port=8005
-proposer_id=aitbc1genesis
-proposer_key=changeme_hex_private_key
-keystore_path=/var/lib/aitbc/keystore
-keystore_password_file=/var/lib/aitbc/keystore/.password
-gossip_backend=broadcast
-gossip_broadcast_url=redis://127.0.0.1:6379
-db_path=/var/lib/aitbc/data/ait-mainnet/chain.db
-mint_per_unit=0
-coordinator_ratio=0.05
-block_time_seconds=60
-enable_block_production=true
-
-# =========================
-# Coordinator API
-# =========================
-APP_ENV=production
-APP_HOST=127.0.0.1
-APP_PORT=8011
-DATABASE__URL=sqlite:///./data/coordinator.db
-BLOCKCHAIN_RPC_URL=http://127.0.0.1:8026
-ALLOW_ORIGINS=["http://localhost:8011","http://localhost:8000","http://8026"]
-JOB_TTL_SECONDS=900
-HEARTBEAT_INTERVAL_SECONDS=10
-HEARTBEAT_TIMEOUT_SECONDS=30
-RATE_LIMIT_REQUESTS=60
-RATE_LIMIT_WINDOW_SECONDS=60
-CLIENT_API_KEYS=["client_prod_key_use_real_value"]
-MINER_API_KEYS=["miner_prod_key_use_real_value"]
-ADMIN_API_KEYS=["admin_prod_key_use_real_value"]
-HMAC_SECRET=change_this_to_a_32_byte_random_secret
-JWT_SECRET=change_this_to_another_32_byte_random_secret
-
-# =========================
-# Marketplace Web
-# =========================
-VITE_MARKETPLACE_DATA_MODE=live
-VITE_MARKETPLACE_API=/api
-VITE_MARKETPLACE_ENABLE_BIDS=true
-VITE_MARKETPLACE_REQUIRE_AUTH=false
-
-# =========================
-# Notes
-# =========================
-# For production: move secrets to a secrets manager and reference via secretRef
-# Validate config: python config/security/environment-audit.py --format text