- Add TestResolveM3UPath with 7 cases: abs, relative, second root, no match, empty roots, nil knownPaths
- Add TestToRelativePathMultiRoot with 5 cases: first root, second root, no root, empty roots, empty string
- Add TestRemoveM3UEntriesMultiRoot: entries from different roots removed correctly
- Add TestFindM3UEntryMultiRoot: entry relative to second root found
- Add TestReplaceM3UEntryPathsMultiRoot: replacement under second root applied