chore: add .gitignore with Python, Node, env, and ChromaDB exclusions

.gitignore

@@ -0,0 +1,71 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Virtual environments
+venv/
+ENV/
+env/
+.venv
+
+# IDEs
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Environment variables
+.env
+.env.local
+.env.*.local
+
+# ChromaDB
+chroma_db/
+
+# Uploads
+backend/uploads/*
+!backend/uploads/.gitkeep
+
+# Node.js
+node_modules/
+frontend/dist/
+frontend/build/
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Test coverage
+.coverage
+htmlcov/
+.pytest_cache/
+
+# Docker
+.dockerignore
+
+# Misc
+*.bak
+*.tmp