feat: add locale formatting config and update notebook outputs

Add configurable locale/display formatting environment variables
(`PALLADIUM_CURRENCY_SYMBOL`, `PALLADIUM_THOUSANDS_SEP`,
`PALLADIUM_DECIMAL_SEP`) to support regional number formatting in the
Streamlit app. Update `.env.example` with documentation for these new
variables.

Also refresh `00_setup.ipynb` with current execution outputs reflecting
a live Athena connection with report templates, a selected client
(Global Guardian Insurance, ID=2), and resolved NameError in assumption
override cells.

app/components/charts.py

@@ -9,24 +9,24 @@ from core.notebook_helpers import charts as core_charts
 
 def cashflow(yearly_breakdown, *, initial_cost: float = 0.0) -> None:
     fig = core_charts.cashflow_chart(yearly_breakdown, initial_cost=initial_cost)
-    st.plotly_chart(fig, use_container_width=True)
+    st.plotly_chart(fig, width="stretch")
 
 
 def benefits_bar(items) -> None:
     fig = core_charts.benefits_bar(items)
-    st.plotly_chart(fig, use_container_width=True)
+    st.plotly_chart(fig, width="stretch")
 
 
 def cost_pie(items) -> None:
     fig = core_charts.cost_breakdown_pie(items)
-    st.plotly_chart(fig, use_container_width=True)
+    st.plotly_chart(fig, width="stretch")
 
 
 def scenario_bars(scenarios) -> None:
     fig = core_charts.scenario_comparison(scenarios)
-    st.plotly_chart(fig, use_container_width=True)
+    st.plotly_chart(fig, width="stretch")
 
 
 def waterfall(values) -> None:
     fig = core_charts.waterfall(values)
-    st.plotly_chart(fig, use_container_width=True)
+    st.plotly_chart(fig, width="stretch")