feat(drive): add ClientUID support for draft ownership tracking

[tomholford]

Summary

Add ClientUID field to Drive API types per official Proton Drive OpenAPI spec.

This is a step towards resolving henrybear327/Proton-API-Bridge#16

Changes

• CreateFileReq.ClientUID: identifies which client created a file draft
• CheckAvailableHashesReq.ClientUID: filters pending drafts by client UIDs
• CheckAvailableHashesRes / PendingHashData: returns draft ownership info

Why

Enables clients to:

• Safely auto-replace their own failed upload drafts
• Avoid overwriting concurrent uploads from other clients

This is critical for reliable file uploads - when an upload fails partway through, it leaves an orphaned draft. Without ClientUID, clients cannot distinguish between:

• Their own failed drafts (safe to replace)
• Another client's active upload (should NOT replace)

Reference

These types match the official ProtonDriveApps/sdk driveTypes.ts which is auto-generated from the Proton Drive OpenAPI spec:

// From sdk/js/sdk/src/internal/apiService/driveTypes.ts
CreateFileDto: {
    ClientUID: string | null;  // "Client unique ID. Useful for marking client's drafts..."
    // ...
}

CheckAvailableHashesRequestDto: {
    ClientUID: string[] | null;  // "Client UID list to filter pending drafts with..."
}

PendingHashResponseDto: {
    ClientUID?: string | null;
}