* Move shared `fichiers-fragment.php` from `partage/` to `templates/partials/form/`
and update all include/require references
* `.gitignore`: exclude SQLite WAL/SHM journal files
* FilePond UI:
* change uploaded file block border state from yellow to green
* restyle image previews to use site light-theme colors
* Edit mode:
* remove custom existing-file preview list implementation
* preload existing files directly into FilePond pools
* include `cover` and `note_intention` assets in FilePond-managed state
* Remove obsolete upload progress bar UI and related JS includes
* Remove deprecated `Écriture` + `Image` format types from upload flow/configuration
- toast-fragment.php: 204 early-exit now also checks flash['warning'];
previously the warning was consumed by consumeFlash() then silently dropped
- partage/index.php: store warning as plain text; htmlspecialchars() applied
once at render time — previously htmlspecialchars() was called inside the
stored string then again at output, producing ' entities etc.
- partage/index.php: flash-warning div gets id + tabindex=-1; inline JS
scrolls it into view and focuses it on DOMContentLoaded
- admin/footer.php: htmx:afterSettle listener focuses .toast--warning after
HTMX injects the toast fragment into #toast-region