fix(gui): clarifier aide et disponibilite moteurs

Passe theme clair, libelles utilisateur, aides conteneurs, recherche de mise a jour et indication honnete des moteurs optionnels non embarques. Tests GUI unitaires: 126 passed.

tests/unit/test_gui_v6_theme.py

@@ -15,7 +15,7 @@ _REQUIRED_TOKENS = {
 
 def test_four_themes_present():
     assert set(theme_mod.PALETTES) == {"sombre", "clair", "medical", "neutre"}
-    assert theme_mod.DEFAULT_THEME == "sombre"
+    assert theme_mod.DEFAULT_THEME == "clair"
 
 
 @pytest.mark.parametrize("name", ["sombre", "clair", "medical", "neutre"])
@@ -31,11 +31,11 @@ def test_palette_has_all_tokens(name):
 
 
 def test_default_palette_matches_mockup():
-    p = theme_mod.get_palette("sombre")
-    assert p["bg"] == "#1a1a2e"
-    assert p["card"] == "#16213e"
-    assert p["primary"] == "#e94560"
-    assert p["accent"] == "#f5a623"
+    p = theme_mod.get_palette(theme_mod.DEFAULT_THEME)
+    assert p["bg"] == "#cdd2da"
+    assert p["card"] == "#ffffff"
+    assert p["primary"] == "#c93050"
+    assert p["accent"] == "#b45309"
 
 
 def test_get_palette_fallback():