types/upload: add missing v4 large-file part metadata fields

[goanpeca]

Summary

The current native API docs include additional metadata on large-file part operations that the SDK response types do not expose.

Evidence

• b2_upload_part response includes contentMd5.
• b2_list_parts part entries include contentMd5.
• b2_copy_part response includes contentMd5, serverSideEncryption, and uploadTimestamp.
• b2_start_large_file response includes replicationStatus.
• Existing issue types: BucketInfo phantom top-level defaultRetention; large-file responses omit retention/legalHold/SSE echo #41 already covers related large-file retention/legal-hold/SSE echo fields.

Impact

Typed consumers lose access to documented response metadata and may need unsafe casts to read fields returned by B2.

Acceptance criteria

• Add contentMd5 to upload-part and list-parts response types.
• Add contentMd5, serverSideEncryption, and uploadTimestamp to copy-part response types.
• Add replicationStatus to start-large-file response types.
• Coordinate with types: BucketInfo phantom top-level defaultRetention; large-file responses omit retention/legalHold/SSE echo #41 for retention/legal-hold/SSE echo fields.
• Update simulator fixtures and response-shape tests.

Versioning note

This should be additive because it only exposes fields B2 may already return.

[goanpeca]

Implementation direction update:

This remains good v0.2.0 additive work. These are response fields B2 may already return, so exposing them in TypeScript should not be breaking.

Simulator note: simulator fixtures/responses should include the canonical current fields (contentMd5, uploadTimestamp, serverSideEncryption, replicationStatus where applicable) so tests catch response-shape drift.