chore: initialize git repo, add matplotlib dep, extend config

- Add .gitignore for Python/data/models
- Add matplotlib>=3.8.0 for eval plots
- Add PretrainConfig, FinetuneConfig, BalabitAdapterConfig, EvalConfig dataclasses

.gitignore

@@ -0,0 +1,32 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+.venv/
+.pytest_cache/
+
+# IDE
+.idea/
+.vscode/
+
+# uv
+uv.lock.bak
+
+# Data & models — large binary, do NOT commit
+data/traces.jsonl
+data/scroll_traces.jsonl
+data/pretrain_traces.jsonl
+data/models_v2/
+data/models_v2_pretrained/
+data/scroll_models/
+data/eval_reports/
+data/balabit_raw/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Playwright artifacts
+.playwright-mcp/