feat: add lockInfo to driveItem

[dschmidt]

Adds lock metadata to driveItem as the top-level lockInfo property, matching the MS Graph beta lockInfo resource (published 2026-06-30): lockType (none, exclusive, shared, unknownFutureValue), createdDateTime, expirationDateTime and owners. One extension: @libre.graph.appName carries the application holding the lock (WOPI/app locks), which MS Graph does not model.

Everything is read straight off the CS3 lock: lockType from Lock.Type, createdDateTime from the locktime opaque, expirationDateTime from Lock.Expiration, owners from Lock.User plus the lockownername opaque, @libre.graph.appName from Lock.AppName. WebDAV exposes the same state only in mangled form (app name folded into the d:owner string, expiration as a relative d:timeout).

The beta POST .../lock and releaseLock endpoints are not part of this PR; WebDAV LOCK/UNLOCK stays the write path for now. They can follow as their own PR (including whether to relax the 30 minute cap via config).

[butonic]

The MS Graph Beta endpoint has driveItem.lock: https://learn.microsoft.com/en-us/graph/api/driveitem-lock?view=graph-rest-beta&tabs=http

We can use it as is AFAICT. The driveItem.lockInfo has createdDateTime, expirationDateTime, createdDateTime (which is always exclusive) and an owner property, which is a Collection(userIdentity).

It has no appName, bet we can add it as a @libre.graph.appName property on the lockInfo.

Related:
https://learn.microsoft.com/en-us/graph/api/driveitem-releaselock?view=graph-rest-beta&tabs=http

Remarks:

• In MS Graph Lock duration is capped at 30 minutes per request. I'm happy to allow higher values ... armaybe an ENV configurable amount.
• Only exclusive locks are currently supported. The lockType in the response is always exclusive.
• The createdDateTime and expirationDateTime are returned in UTC.
• After release, the file's lock state is cleared: a subsequent call to GET /drives/{drive-id}/items/{item-id}?$select=lockInfo returns the lockInfo facet with lockType none and an empty owners array.

[dschmidt]

Tremendous find, that landed in the beta docs on 2026-06-30, a few weeks before this PR was drafted.

Reworked to lockInfo as is plus @libre.graph.appName for the app lock, as a top-level driveItem property per the driveItem resource doc (the lockinfo page claims it sits on the file facet, but the driveItem property table and JSON representation say otherwise).

The lock/releaseLock endpoints are left for their own PR, WebDAV LOCK stays the write path for now.