[marcmy]

What changed

• adds a collapsible, virtualized compression Details view with the actual per-file worklist
• shows queued, processing, completed, and failed states with original/on-disk sizes
• follows the current file automatically while compression progresses
• reports the Windows/WOF failure reason when a file operation fails
• centers the main percentage in white over the progress bar
• hosts the stop/save-progress prompt inside CompactGUI so it stays over the main window on the correct monitor
• makes the prompt's X cancel the stop request, resuming only when the stop dialog itself caused the pause

Why

Large compression jobs previously exposed only an overall percentage, which made it difficult to see what CompactGUI was doing or diagnose individual file failures. The stop prompt also opened as an independent window, so Windows could place it on a different monitor, and closing it was indistinguishable from choosing Leave as is.

Impact

Users can inspect long-running compression, decompression, and undo operations without sacrificing UI responsiveness. Stop decisions remain explicit, while dismissing the prompt safely abandons the stop request.

Per-file progress remains intentionally indeterminate while Windows performs an individual WOF operation because that API is atomic and does not expose byte-level progress.

Validation

• strict Release build with warnings treated as errors
• self-contained Windows x64 publish
• zero compiler warnings or errors
• manual confirmation that the Details UI and in-window stop prompt behave correctly