set CalVer 2026.03.13, remove legacy code

Remove old Vorleser/, VorleserMac/, Vendor/ directories and
Vorleser.xcodeproj. Add MARKETING_VERSION and
CURRENT_PROJECT_VERSION to both targets in project.yml.

project.yml

@@ -31,6 +31,8 @@ targets:
 		settings:
 			base:
 				PRODUCT_BUNDLE_IDENTIFIER: de.felixfoertsch.vorleser
+				MARKETING_VERSION: "2026.03.13"
+				CURRENT_PROJECT_VERSION: "1"
 				INFOPLIST_VALUES: >-
 					UIBackgroundModes=(audio);
 					UILaunchScreen={};
@@ -61,6 +63,8 @@ targets:
 		settings:
 			base:
 				PRODUCT_BUNDLE_IDENTIFIER: de.felixfoertsch.vorleser.mac
+				MARKETING_VERSION: "2026.03.13"
+				CURRENT_PROJECT_VERSION: "1"
 		resources:
 			- path: Resources/Models
 			  buildPhase: resources