Fix Docker push/pull: add PATCH endpoint for chunked uploads

- Add PATCH handler for /v2/{name}/blobs/uploads/{uuid} to support
  chunked blob uploads (Docker sends data chunks via PATCH)
- Include Range header in PATCH response to indicate bytes received
- Add Docker-Content-Digest header to GET manifest responses
- Store manifests by both tag and digest for proper pull support
- Add parking_lot dependency for upload session state management

nora-registry/Cargo.toml

@@ -41,6 +41,7 @@ chrono = { version = "0.4", features = ["serde"] }
 thiserror = "2"
 tower_governor = "0.8"
 governor = "0.10"
+parking_lot = "0.12"
 
 [dev-dependencies]
 tempfile = "3"