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.

00_setup.ipynb

@@ -22,7 +22,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 6,
    "id": "53fcc345",
    "metadata": {},
    "outputs": [
@@ -32,7 +32,7 @@
        "Palladium(root='palladium', athena='not tested')"
       ]
      },
-     "execution_count": 1,
+     "execution_count": 6,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -66,7 +66,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 7,
    "id": "853aaab8",
    "metadata": {},
    "outputs": [
@@ -102,7 +102,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 8,
    "id": "9b7fcc97",
    "metadata": {},
    "outputs": [
@@ -110,7 +110,7 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "✅ Athena connected — https://athena.ouranos.helu.ca (0 report templates visible)\n"
+      "✅ Athena connected — https://athena.ouranos.helu.ca (1 report templates visible)\n"
      ]
     },
     {
@@ -119,11 +119,11 @@
        "{'status': 'ok',\n",
        " 'base_url': 'https://athena.ouranos.helu.ca',\n",
        " 'authenticated': True,\n",
-       " 'reports_found': 0,\n",
-       " 'timestamp': '2026-06-10T06:45:10.418874'}"
+       " 'reports_found': 1,\n",
+       " 'timestamp': '2026-06-10T07:08:06.947037'}"
       ]
      },
-     "execution_count": 3,
+     "execution_count": 8,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -144,16 +144,69 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 9,
    "id": "83edbe4d",
    "metadata": {},
    "outputs": [
     {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "No TEI report templates yet — studies/202602_AmazonConnect/notebooks/00_provision.ipynb creates one.\n"
-     ]
+     "data": {
+      "text/html": [
+       "<div>\n",
+       "<style scoped>\n",
+       "    .dataframe tbody tr th:only-of-type {\n",
+       "        vertical-align: middle;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe tbody tr th {\n",
+       "        vertical-align: top;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe thead th {\n",
+       "        text-align: right;\n",
+       "    }\n",
+       "</style>\n",
+       "<table border=\"1\" class=\"dataframe\">\n",
+       "  <thead>\n",
+       "    <tr style=\"text-align: right;\">\n",
+       "      <th></th>\n",
+       "      <th>id</th>\n",
+       "      <th>name</th>\n",
+       "      <th>vendor</th>\n",
+       "      <th>version</th>\n",
+       "      <th>status</th>\n",
+       "      <th>analysis_period_years</th>\n",
+       "      <th>discount_rate</th>\n",
+       "      <th>field_count</th>\n",
+       "      <th>instance_count</th>\n",
+       "    </tr>\n",
+       "  </thead>\n",
+       "  <tbody>\n",
+       "    <tr>\n",
+       "      <th>0</th>\n",
+       "      <td>xsUTbjh4iDnJ</td>\n",
+       "      <td>Amazon Connect 2026</td>\n",
+       "      <td>AWS</td>\n",
+       "      <td>1.0</td>\n",
+       "      <td>active</td>\n",
+       "      <td>3</td>\n",
+       "      <td>0.1000</td>\n",
+       "      <td>11</td>\n",
+       "      <td>0</td>\n",
+       "    </tr>\n",
+       "  </tbody>\n",
+       "</table>\n",
+       "</div>"
+      ],
+      "text/plain": [
+       "             id                 name vendor version  status  \\\n",
+       "0  xsUTbjh4iDnJ  Amazon Connect 2026    AWS     1.0  active   \n",
+       "\n",
+       "   analysis_period_years discount_rate  field_count  instance_count  \n",
+       "0                      3        0.1000           11               0  "
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
     }
    ],
    "source": [
@@ -172,7 +225,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 10,
    "id": "a247bedd",
    "metadata": {},
    "outputs": [
@@ -209,6 +262,30 @@
     "2. **Work the study** → notebooks `01_benefits` → `04_export` in the same folder.\n",
     "3. **Interactive data entry** → `make app` (or `streamlit run app/main.py`)."
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "d20d824f-e464-4ff7-8191-10c2495842a0",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "630ee935-7c7b-47e5-9c13-6285316823e2",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "7eba3877-8e51-443f-9953-9d0a48425f9f",
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {