feat: US-002 - Guard against data loss in archive.sh

lib/archive.sh

@@ -75,6 +75,12 @@ archive_run() {
         [ -d "$LOOP_DIR/contracts" ] && cp -r "$LOOP_DIR/contracts" "$archive_dir/"
     fi
 
+    # Verify the archive received content before deleting originals
+    if ! find "$archive_dir" -maxdepth 1 -type f | read -r; then
+        log "WARNING: Archive directory $archive_dir is empty after copy — skipping deletion of originals to prevent data loss"
+        return
+    fi
+
     # Clean up old run's artifacts (progress.md, contracts — NOT prd.json which belongs to new feature)
     rm -f "$LOOP_DIR/progress.md"
     rm -rf "$LOOP_DIR/contracts"