Add branded web loading screen

scripts/autoload/ui_theme_service.gd

@@ -13,6 +13,7 @@ var _is_dark := true
 func _enter_tree() -> void:
 	_is_dark = _load_preference()
 	Style.set_dark_mode(_is_dark)
+	_sync_web_preference()
 
 
 func is_dark_mode() -> bool:
@@ -25,6 +26,7 @@ func set_dark_mode(value: bool) -> void:
 	_is_dark = value
 	Style.set_dark_mode(_is_dark)
 	_save_preference()
+	_sync_web_preference()
 	theme_changed.emit(_is_dark)
 
 
@@ -59,3 +61,14 @@ func _save_preference() -> void:
 	config.set_value(SETTINGS_SECTION, SETTINGS_KEY, "dark" if _is_dark else "light")
 	if config.save(SETTINGS_PATH) != OK:
 		push_warning("Unable to save color scheme preference.")
+
+
+func _sync_web_preference() -> void:
+	if not OS.has_feature("web"):
+		return
+	JavaScriptBridge.eval(
+		"try { window.localStorage.setItem('medmind-color-scheme', %s); } catch (error) { console.warn('Theme preference storage is unavailable.', error); }" % JSON.stringify(
+			"dark" if _is_dark else "light"
+		),
+		true
+	)