Commons Compress declares its LZMA/LZMA2 support against org.tukaani:xz as an *optional* dependency, so nothing pulled it in transitively and nothing failed at build time. The app nevertheless advertised .xz as extractable, so the first user to open one would have got NoClassDefFoundError: org/tukaani/xz/FilterOptions. XZCompressorInputStream references org/tukaani/xz/XZInputStream directly. The library is now declared, and a round-trip test covers the path that was silently missing.
That same library is what 7z needs, and Commons Compress already ships a pure-Java 7z reader, so 7z extraction costs no native code and no further dependency. The docs had assumed the format was off limits and said so in three places, including the customer-facing store copy.
7z is the only format here that cannot arrive through a stream: its header sits at the end of the file, so the reader has to seek. That is now a capability the backend advertises, StorageSource.openSeekable: the all-files backend answers with a real FileChannel, the SAF fallback with null, so folder mode reports needs-a-seekable-file instead of failing obscurely. Entry names go through the same ArchivePath.safeRelativePath zip-slip guard. 7z creation stays deferred.
The last commit shipped the screenshots and the two-pane layout but left the roadmap and README saying otherwise. Also corrects the stated reason 7z is unsupported: RAR really does need native code, but SevenZFile is already inside the Commons Compress jar this app ships.
A window at or above Material expanded breakpoint (840dp) now splits into a master pane and a detail pane: tapping a row highlights it and the second pane shows a folder children, or a preview plus the metadata for a file. Opening moves to a double tap on wide windows only; phones (~411dp) and the 7-inch in portrait (~600dp) keep their layout and their tap behaviour.
Found while taking the tablet screenshots: the app had no large-screen layout at all, so on a 2560x1600 canvas every row was 2560px wide with its content stranded in the left ~240px.
The tablet sets are re-shot on this build. That also caught a blank capture (7-inch 01-roots) that had already been committed: a headless AVD draws its system bars before Compose composes its first frame, so the file was not obviously empty. make-store-screenshots.sh now measures each capture app area and refuses to normalise one that is blank.
SoftwareApp