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/views/versions.py

@@ -4,7 +4,9 @@ from __future__ import annotations
 
 import streamlit as st
 
-from app.pages._helpers import safe
+from app.utils import icon
+
+from app.views._helpers import safe
 from core.tei_client import TEIClient
 
 
@@ -17,6 +19,7 @@ def _diff_rows(a: dict[str, dict], b: dict[str, dict]) -> list[dict]:
     """Return one row per field with side-by-side year values."""
     keys = sorted(set(a.keys()) | set(b.keys()))
     rows: list[dict] = []
+
     def _years_of(v: dict) -> dict:
         """Accept both friendly (year_values) and wire (nested years) shapes."""
         if isinstance(v.get("year_values"), dict):
@@ -54,7 +57,10 @@ def _diff_rows(a: dict[str, dict], b: dict[str, dict]) -> list[dict]:
 
 
 def render(client: TEIClient, tool: dict) -> None:
-    st.header("🕒 Versions")
+    st.markdown(
+        f"<h2>{icon('clock-history')} Versions</h2>",
+        unsafe_allow_html=True,
+    )
     public_id = tool["id"]
 
     versions = safe(client.list_versions, public_id) or []
@@ -63,7 +69,7 @@ def render(client: TEIClient, tool: dict) -> None:
     )
 
     # Save new version
-    with st.expander("➕ Save current state as a new version", expanded=not versions):
+    with st.expander("Save current state as a new version", expanded=not versions):
         note = st.text_area(
             "Version note",
             placeholder=(
@@ -71,7 +77,7 @@ def render(client: TEIClient, tool: dict) -> None:
                 "raised legacy license cost from $160 to $180/agent.'"
             ),
         )
-        if st.button("💾 Save version", disabled=not note.strip()):
+        if st.button("Save version", disabled=not note.strip()):
             result = safe(client.save_version, public_id, note.strip())
             if result:
                 st.success(
@@ -102,7 +108,8 @@ def render(client: TEIClient, tool: dict) -> None:
                 "Note": v.get("note", ""),
             }
         )
-    st.dataframe(rows, use_container_width=True, hide_index=True)
+    st.dataframe(rows, width="stretch", hide_index=True)
+
 
     # Compare two versions
     st.subheader("Compare")
@@ -132,4 +139,5 @@ def render(client: TEIClient, tool: dict) -> None:
     if not diff:
         st.success("No value differences between these versions.")
     else:
-        st.dataframe(diff, use_container_width=True, hide_index=True)
+        st.dataframe(diff, width="stretch", hide_index=True)
+