[faizollah]

A run now writes the crate straight into the output folder, which is renamed from fl_crate_out to flwrcrate-ro-crate:

flwrcrate-ro-crate/
├── ro-crate-metadata.json
├── metrics_log.json
└── <model file>

• The default output_dir is flwrcrate-ro-crate, and that folder is the crate itself, with no ro-crate/ sub-folder. The metrics log is written straight into it (ro-crate-py skips copying a file onto itself).
• captured_metadata.json is still written during the run, so a crash leaves a record, but it is deleted once the crate is written.
• Building the crate warns about files in the folder that flwrCrate didn't write (hidden files such as .DS_Store are ignored), since they would travel with the crate if the folder is shared.
• The README, the PyTorch example, .gitignore and the e2e workflow use the new folder.

Breaking change: the crate moves from <output_dir>/ro-crate/ro-crate-metadata.json to <output_dir>/ro-crate-metadata.json, so this should go in 0.5.0 with a note in the release notes.

Tests: the lifecycle test checks the folder holds exactly those three files, and two new tests cover keeping the capture when the crate can't be written, and the warning about other files. main is merged in; the only conflict was the path in the e2e validation step.

Closes #26