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

package.py

@@ -23,7 +23,7 @@ Manifest schema (all keys optional except `contents`):
       extensions: [".lua", ".xml", ".toc"]
     contents:
       - src: .                  # path in the repo (file or dir)
-        dest: Interface/GlueXML # in-MPQ path (forward slashes; converted to \)
+        dest: Interface/GlueXML # in-MPQ path (forward slashes become backslashes)
         ignore:                 # glob patterns, matched against repo-relative paths
           - ".git/**"
           - ".gitea/**"