Add MPQ verify modes, harden CI assertions, fix CRLF/docstring

- mpqpack gains --list and --cat (StormLib-backed) for reading archives back
- CI now asserts the archive lists the expected file and that version
  substitution landed inside the MPQ, not just that a file exists
- Dockerfile strips CRLF from entrypoint/package so local Windows builds work
- drop invalid escape in package.py docstring

.gitignore

@@ -2,3 +2,6 @@ dist/
 test/dist/
 *.mpq
 *.o
+# local validation helpers (not needed in CI)
+test/stub_mpqpack.py
+test/mpqpack.cmd