feat: add GenesysCX study and fix Streamlit chart key collisions

- Add 202512_GenesysCX TEI study (config, seed data, notebooks, README)
  with NPV $10.8M / ROI 266% including AI-token cost line
- Add explicit `key` parameter to all chart wrappers in app/components
  to prevent StreamlitDuplicateElementId errors when the same figure
  type renders across Summary/Benefits/Costs tabs
- Render benefits bar and cost pie charts on their respective tabs
- Add benefits_vs_costs_by_year chart wrapper

studies/202512_GenesysCX/ctm-token-calculator/requirements.txt

@@ -0,0 +1,9 @@
+streamlit>=1.30
+pandas>=2.0
+numpy>=1.25
+plotly>=5.18
+openpyxl>=3.1
+pydantic>=2.0
+jupyterlab>=4.0
+ipywidgets>=8.0
+pytest>=7.4