add trailing slash to restore_path for trashed directories

[JF-Cozy]

Add a trailing / to restore_path (path of the parent folder) when trashing files and directories. This prevents false positives when querying the trash of shared drives with similar names — without it, a $gte: "/Shared Drives/Test" query also captures files from "/Shared Drives/Test 2/...".

No impact on RestoreDir / RestoreFile — DirByPath uses path.Clean which strips trailing slashes, and path.Join normalizes paths.

App must change fetch from

    Q(FILES_DOCTYPE)
      .where({
        dir_id: TRASH_DIR_ID,
        type,
        name: { $gt: null },
        restore_path: { $gte: path, $lt: path + '\ufff0' }
      })

to

    Q(FILES_DOCTYPE)
      .where({
        dir_id: TRASH_DIR_ID,
        type,
        name: { $gt: null },
        restore_path: { $gte: path + '/', $lt: path + '\ufff0' }

[shepilov]

what will be for the files with "/" as an oldpath? I think we should keep root unchanged

[shepilov]

@JF-Cozy is it sitll relevant for displaying trash in admin panel?

[JF-Cozy]

Not prioritized today, and a more robust approach using referenced_by would be better, so we can close it for now.

Here's a full summary of the problem and solutions:

Context

When two shared drives have names sharing a common prefix (e.g. "Shared" and "Shared Drive"), the trash view of one drive leaks files from the other. The cozy-admin trash query scopes the listing with a lexicographic range on restore_path:

restore_path: { $gte: path, $lt: path + '\ufff0' }

Because "Shared" is a string prefix of "Shared Drive", a $gte: "/Drives/Shared" also matches /Drives/Shared Drive/... — a classic string-prefix collision, not an identity match.

Approach A — trailing slash on restore_path (this PR)

Append / to restore_path at trash time on the backend, and use path + '/' as the lower bound in the app query. The / makes the bound a directory delimiter: /Drives/Shared/ no longer matches /Drives/Shared Drive/... since "Shared D..." > "Shared/".

Pros: minimal diff, immediate fix.
Cons: requires a coordinated change on the app side (both must agree on the /); does not backfill already-trashed docs created before the fix; the root edge case (path.Dir("/") → "//") needs a guard; the contract is implicit across two repos.

Approach B — scope by referenced_by (long-term)

Scope the trash to a shared drive via a referenced_by selector pointing at the sharing id, instead of matching the human-readable path. This is the more robust model: it keys on a stable document identity, so no string-prefix collision is possible and it is immune to drive renames.

This is not a drop-in swap today — it requires:

• per-file tagging (currently only the shared-drive root carries referenced_by {type: io.cozy.sharings, id: sharingID}, children do not),
• a Mango index on referenced_by (only a CouchDB view exists today),
• a _find route for shared drives that injects the selector server-side.

Once in place, the app query becomes identity-based and the path-prefix class of bug disappears entirely.