feat: Rename executable to 'Umbrix Start.exe' (no BAT, antivirus-safe)

- Set OUTPUT_NAME to 'Umbrix Start' in runner/CMakeLists.txt
- Users see clear 'Umbrix Start.exe' file to run
- No BAT files that could be blocked by antivirus
- README.txt guides users to the main executable

windows/runner/CMakeLists.txt

@@ -16,6 +16,9 @@ add_executable(${BINARY_NAME} WIN32
   "runner.exe.manifest"
 )
 
+# Set the output name with space
+set_target_properties(${BINARY_NAME} PROPERTIES OUTPUT_NAME "Umbrix Start")
+
 # Apply the standard set of build settings. This can be removed for applications
 # that need different build settings.
 apply_standard_settings(${BINARY_NAME})