feat(gui): sidebar sections + non-technical tool labels

Sidebar nav now groups tools under Data Review / Data Cleaners /
Transformations / Automations via st.navigation, replacing the flat
auto-discovered list. Tool display names switch to action-first
phrasing (Find Duplicates, Fix Missing Values, Find Unusual Values,
Standardize Formats, Clean Text, Quality Check, Map Columns, Combine
Files, Automated Workflows) in EN + ES packs and on each page's H1.

The Data Cleaners section follows the requested order: Missing
Values → Outliers → Text Cleaner → Format Standardizer → Deduplicator
→ Quality Check. (Text Cleaner kept inside cleaners since the request
didn't list it but the tool still ships.) Registry now carries a
section field; helpers added: tools_in_section(), section_label().

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/gui/test_chrome.py

@@ -168,11 +168,11 @@ class TestHomeToolGridLocalization:
     English names. Pin a few representative ones."""
 
     @pytest.mark.parametrize("needle", [
-        "Eliminador de duplicados",
-        "Limpiador de texto",
-        "Estandarizador de formatos",
-        "Gestor de valores faltantes",
-        "Mapeador de columnas",
+        "Buscar duplicados",
+        "Limpiar texto",
+        "Estandarizar formatos",
+        "Corregir valores faltantes",
+        "Mapear columnas",
     ])
     def test_es_tool_name_on_home_grid(self, home_app, needle):
         with_language(home_app, "es")