feat: read platform launchers in verify and packs

A names_searched list is one place the launcher fills with the first name it finds, so a core file it would never open once another name of the list is held is not reported missing. A place no declared file and no packed core file fills receives, under the launcher's name, a file the core accepts by content. The layer is applied inside find_undeclared_files, which verify and the pack builder both read, and a test reads their source to keep it there.

.github/workflows/deploy-site.yml

@@ -22,6 +22,7 @@ on:
       - "scripts/generate_site.py"
       - "scripts/hashing.py"
       - "scripts/largefiles.py"
+      - "scripts/launchers.py"
       - "scripts/mkdocs_hooks.py"
       - "scripts/nativemode.py"
       - "scripts/packextras.py"