fix(scripts): resolve tar compression conflict in log-manager.sh

The archive command was using conflicting compression options:
- Removed -z flag (built-in gzip)
- Kept --use-compress-program for custom compression level

This fixes the 'Conflicting compression options' error when running
./scripts/log-manager.sh archive

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/log-manager.sh

@@ -504,7 +504,7 @@ EOF
 
     # Create optimized archive
     cd "$ARCHIVE_DIR"
-    tar -czf "${archive_name}.tar.gz" --use-compress-program="gzip -${COMPRESS_LEVEL:-9}" -C "$(dirname "$temp_dir")" "$(basename "$temp_dir")"
+    tar -cf "${archive_name}.tar.gz" --use-compress-program="gzip -${COMPRESS_LEVEL:-9}" -C "$(dirname "$temp_dir")" "$(basename "$temp_dir")"
 
     # Verify archive integrity
     if tar -tzf "${archive_name}.tar.gz" >/dev/null 2>&1; then