Update .gitignore to exclude visualization build artifacts

- Exclude visualization/**/node_modules/
- Exclude visualization/**/bundle_* files
- Exclude visualization/**/temp_* files
- Exclude test HTML files
- Exclude root node_modules and package-lock.json

🤖 Generated with Claude Code

.gitignore

@@ -5,3 +5,18 @@ input
 *.swp
 tmp
 logs
+
+# Visualization build artifacts
+visualization/**/node_modules/
+visualization/**/bundle_*.js
+visualization/**/bundle_*.css
+visualization/**/temp_*.jsx
+
+# Test HTML files
+test_*.html
+*_output.html
+query_graph_*.html
+
+# Root node_modules (should only be in subfolders)
+node_modules/
+package-lock.json