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/main.py

@@ -24,6 +24,7 @@ if str(_ROOT) not in sys.path:
 import streamlit as st
 
 from core.tei_client import AthenaAPIError, TEIClient
+from app.utils import icon, inject_icons
 
 st.set_page_config(
     page_title="Palladium — TEI Calculator",
@@ -32,6 +33,7 @@ st.set_page_config(
 )
 
 
+
 @st.cache_resource(show_spinner=False)
 def get_client() -> TEIClient:
     return TEIClient()
@@ -75,7 +77,9 @@ def _crm_engagements(_client: TEIClient, client_name: str) -> list[dict]:
 
 def sidebar_tool_picker(client: TEIClient) -> dict | None:
     """Sidebar: pick an existing TEI tool or create one from a report template."""
-    st.sidebar.title("🛡️ Palladium")
+    st.sidebar.markdown(
+        f"{icon('shield-fill')} **Palladium**", unsafe_allow_html=True
+    )
     st.sidebar.caption("TEI Calculator")
 
     tools = _safe_call(client.list_tools) or []
@@ -163,15 +167,20 @@ def sidebar_tool_picker(client: TEIClient) -> dict | None:
         st.sidebar.markdown(f"**Public ID**: `{tool.get('id')}`")
         st.sidebar.markdown(f"**Status**: {tool.get('status', '?')}")
         st.sidebar.markdown(f"**Version**: {tool.get('current_version', 0)}")
-        if st.sidebar.button("🔄 Recalculate"):
+        if st.sidebar.button("Recalculate"):
             _safe_call(client.calculate, tool["id"])
-            st.toast("Recalculated.", icon="✅")
+            st.toast("Recalculated.", icon=None)
             st.cache_data.clear()
     return tool
 
 
 def main() -> None:
-    st.title("Palladium — TEI Calculator")
+    inject_icons()
+
+    st.markdown(
+        f"<h1 style='margin-bottom:0'>{icon('shield-fill')} Palladium — TEI Calculator</h1>",
+        unsafe_allow_html=True,
+    )
     try:
         client = get_client()
     except ValueError as e:
@@ -186,14 +195,19 @@ def main() -> None:
         st.info("Pick or create a TEI tool from the sidebar to begin.")
         return
 
-    # Tab navigation — matches `app/pages/*` modules but kept as tabs so all
+    # Tab navigation — matches `app/views/*` modules but kept as tabs so all
     # views share the chosen tool/state without re-querying.
-    tabs = st.tabs(["📊 Summary", "💰 Benefits", "💸 Costs", "🕒 Versions"])
+    #
+    # NOTE: the directory is `app/views/`, NOT `app/pages/`. Streamlit treats a
+    # `pages/` directory next to the entrypoint as auto-discovered multipage
+    # scripts, which would render blank since these modules only define
+    # `render()` and have no top-level output.
+    tabs = st.tabs(["Summary", "Benefits", "Costs", "Versions"])
 
-    from app.pages import benefits as benefits_page
-    from app.pages import costs as costs_page
-    from app.pages import summary as summary_page
-    from app.pages import versions as versions_page
+    from app.views import benefits as benefits_page
+    from app.views import costs as costs_page
+    from app.views import summary as summary_page
+    from app.views import versions as versions_page
 
     with tabs[0]:
         summary_page.render(client, tool)