feat: add systemd sync solution to eliminate repo/active gap

SYSTEMD SYNC: Link active systemd files to repository for automatic sync

Problem Solved:
❌ Gap between repository systemd files and active systemd files
❌ Development changes in repo not reflected in running services
❌ Manual sync required to update systemd configuration
❌ Risk of configuration drift between repo and production

Solution Implemented:
✅ Symbolic links from /etc/systemd/system/ to /opt/aitbc/systemd
✅ Automatic sync script for manual operations
✅ CI/CD workflow for automatic sync on repository changes
✅ Backup mechanism for safe operations
✅ Verification and status checking

Files Created:
1. scripts/link-systemd.sh:
   - Creates symbolic links for all aitbc-* services
   - Handles .d directories automatically
   - Creates backups before making changes
   - Provides comprehensive status reporting

2. scripts/sync-systemd.sh:
   - Alternative copy-based sync method
   - For environments where symbolic links aren't preferred
   - Maintains file independence while keeping sync

3. .gitea/workflows/systemd-sync.yml:
   - Automatic CI/CD sync on repository changes
   - Triggers when systemd files are modified
   - Verifies link creation and service status
   - Provides manual instructions

Benefits:
✅ Active systemd files always match repository
✅ No configuration drift between repo and production
✅ Changes in repo immediately reflected
✅ Automatic sync on every repository update
✅ Safe operations with backups
✅ CI/CD integration for automation

Usage:
- Manual: sudo ./scripts/link-systemd.sh
- CI/CD: Automatic on systemd file changes
- Verification: ls -la /etc/systemd/system/aitbc-*
- Status: sudo systemctl status aitbc-*

This eliminates the gap between repository and active systemd
configuration, ensuring the repository always contains the current
running state and changes are immediately reflected.

scripts/sync-systemd.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+
+# AITBC Systemd Sync Script
+# Syncs repository systemd files to active systemd configuration
+# Eliminates gap between repo and running services
+
+set -e
+
+REPO_SYSTEMD_DIR="/opt/aitbc/systemd"
+ACTIVE_SYSTEMD_DIR="/etc/systemd/system"
+
+echo "=== AITBC SYSTEMD SYNC ==="
+echo "Repository: $REPO_SYSTEMD_DIR"
+echo "Active: $ACTIVE_SYSTEMD_DIR"
+echo
+
+# Check if running as root
+if [[ $EUID -ne 0 ]]; then
+   echo "❌ This script must be run as root (use sudo)"
+   echo "   sudo $0"
+   exit 1
+fi
+
+# Check if repository systemd directory exists
+if [[ ! -d "$REPO_SYSTEMD_DIR" ]]; then
+    echo "❌ Repository systemd directory not found: $REPO_SYSTEMD_DIR"
+    exit 1
+fi
+
+echo "🔍 Scanning for AITBC systemd files..."
+
+# Create backup of current active systemd files
+BACKUP_DIR="/opt/aitbc/systemd-backup-$(date +%Y%m%d-%H%M%S)"
+echo "📦 Creating backup: $BACKUP_DIR"
+mkdir -p "$BACKUP_DIR"
+find "$ACTIVE_SYSTEMD_DIR" -name "aitbc-*" -type f -exec cp {} "$BACKUP_DIR/" \;
+
+# Sync repository files to active systemd
+echo "🔄 Syncing systemd files..."
+
+# Copy all aitbc-* files from repo to active systemd
+for file in "$REPO_SYSTEMD_DIR"/aitbc-*; do
+    if [[ -f "$file" ]]; then
+        filename=$(basename "$file")
+        target="$ACTIVE_SYSTEMD_DIR/$filename"
+        
+        echo "  📄 Syncing: $filename"
+        
+        # Copy file with proper permissions
+        cp "$file" "$target"
+        chmod 644 "$target"
+        
+        # Handle .d directories
+        if [[ -d "${file}.d" ]]; then
+            target_dir="${target}.d"
+            echo "    📁 Syncing directory: ${filename}.d"
+            mkdir -p "$target_dir"
+            cp -r "${file}.d"/* "$target_dir/"
+            chmod 644 "$target_dir"/*
+        fi
+    fi
+done
+
+echo
+echo "🔄 Reloading systemd daemon..."
+systemctl daemon-reload
+
+echo
+echo "✅ Systemd sync completed!"
+echo
+echo "📊 Sync Summary:"
+echo "  Repository files: $(find "$REPO_SYSTEMD_DIR" -name 'aitbc-*' -type f | wc -l)"
+echo "  Active files: $(find "$ACTIVE_SYSTEMD_DIR" -name 'aitbc-*' -type f | wc -l)"
+echo "  Backup location: $BACKUP_DIR"
+echo
+echo "🔧 To restart services:"
+echo "  sudo systemctl restart aitbc-blockchain-node"
+echo "  sudo systemctl restart aitbc-coordinator-api"
+echo "  # ... or restart all AITBC services:"
+echo "  sudo systemctl restart aitbc-*"
+echo
+echo "🔍 To check status:"
+echo "  sudo systemctl status aitbc-*"
+echo
+echo "⚠️  If you need to restore backup:"
+echo "  sudo cp $BACKUP_DIR/* /etc/systemd/system/"
+echo "  sudo systemctl daemon-reload"