Add integration tests covering the full archive extraction pipeline:
- tar.gz containing Python package metadata (single-level)
- zip containing a JAR with MANIFEST.MF (two-level, same format)
- Mixed archive types (zip + tar.gz at same level)
- Depth limit enforcement (3-level zip nesting, limited to 1)
- Extension exclusion filtering
- 3-level mixed format nesting: tar.gz -> zip -> tar.gz -> files
verifying cross-format extraction and full access path chains
- Reverse format crossing: tar.gz -> zip -> tar.gz verifying
content readability at all levels and correct relationship count
Signed-off-by: Thomas Bechtold <thomasbechtold@jpberlin.de>