Initialize encryption and JavaScript reverse-engineering study repository

Document the project structure and setup while excluding local dependencies and IDE settings.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,22 @@
+# Python-generated files
+__pycache__/
+*.py[oc]
+build/
+dist/
+wheels/
+*.egg-info
+
+# Virtual environments
+.venv
+
+# Node.js dependencies
+node_modules/
+
+# IDE settings
+.idea/
+.vscode/
+
+# Local environment files
+.env
+.env.*
+!.env.example