Add 2025 survey data support

The 2025 survey uses a single English-only xlsx (instead of separate
fi/en files) with a restructured schema: compensation is split into
base salary, commission, lomaraha, bonus, and equity components;
working time is h/week instead of percentage; and competitive salary
is categorical instead of boolean. Vuositulot is now synthesized
from the component fields.

Drop COLUMN_MAP_2024, COLUMN_MAP_2024_EN_TO_FI, VALUE_MAP_2024_EN_TO_FI,
read_initial_dfs_2024, read_data_2024, map_sukupuoli, map_vuositulot,
split_boolean_column_to_other, apply_fixups, and the associated gender
value lists and boolean text maps. All of this exists in version history.

- KKPALKKA now includes base salary + commission (median 5500 → 5800)
- Apply map_numberlike to tuntilaskutus and vuosilaskutus columns to
  handle string values like "60 000" and "100 000"
- Filter out zeros when computing tunnusluvut on the index page so
  stats reflect actual reported values

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

template/index.html

@@ -1,8 +1,11 @@
 {% extends "_base.html" %}
+{% macro eur_span(number) -%}
+    <span title="{{ number }}" class="eur" data-number="{{ number }}">{{ number }}&nbsp;€</span>
+{%- endmacro %}
 {% macro tunnusluvut_points(df, col_name, title) %}
-    {% with num_kk = df[pd.to_numeric(df[col_name], errors='coerce').notnull()][col_name] %}
-        <li title="n = {{ num_kk.count() }}">{{ title }}, keskiarvo = {{ num_kk.mean()|round(0) }} €</li>
-        <li title="n = {{ num_kk.count() }}">{{ title }}, mediaani = {{ num_kk.median()|round(0) }} €</li>
+    {% with num_kk = df[col_name][pd.to_numeric(df[col_name], errors='coerce') > 0].dropna() %}
+        <li title="n = {{ num_kk.count() }}">{{ title }}, keskiarvo = {{ eur_span(num_kk.mean()|round(0)) }}</li>
+        <li title="n = {{ num_kk.count() }}">{{ title }}, mediaani = {{ eur_span(num_kk.median()|round(0)) }}</li>
     {% endwith %}
 {% endmacro %}
 {% block body %}
@@ -74,6 +77,15 @@
         International</a> (CC&nbsp;BY&nbsp;4.0).<br>
         Mankelointityökalujen lisenssi on <a href="https://opensource.org/licenses/MIT">MIT</a>.
     </p>
+    <script>
+    for (const eur of document.querySelectorAll(".eur")) {
+      // Try to parse data-number, format as browser-native currency
+      const number = parseFloat(eur.dataset.number);
+      if (!isNaN(number)) {
+        eur.textContent = number.toLocaleString("fi-FI", {style: "currency", currency: "EUR"});
+      }
+    }
+    </script>
 {% endblock %}
 {% block footer %}
     <footer>