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/edge-node-example.yaml

@@ -1,41 +0,0 @@
-# Edge Node Configuration - Example (minimal template)
-edge_node_config:
-  node_id: "edge-node-example"
-  region: "us-east"
-  location: "example-datacenter"
-
-  services:
-    - name: "marketplace-api"
-      port: 8002
-      enabled: true
-      health_check: "/health/live"
-
-  network:
-    bandwidth_mbps: 500
-    ipv6_support: true
-    latency_optimization: true
-
-  resources:
-    cpu_cores: 4
-    memory_gb: 16
-    storage_gb: 200
-    gpu_access: false  # set true if GPU available
-
-  security:
-    firewall_enabled: true
-    rate_limiting: true
-    ssl_termination: true
-
-  monitoring:
-    metrics_enabled: true
-    health_check_interval: 30
-    log_level: "info"
-
-  load_balancing:
-    algorithm: "round_robin"
-    weight: 1
-
-  performance_targets:
-    response_time_ms: 100
-    throughput_rps: 200
-    error_rate: 0.01