test: add comprehensive unit tests for storage and auth

- LocalStorage tests: put/get, list, stat, health_check, nested dirs
- S3Storage tests with wiremock HTTP mocking
- Auth/htpasswd tests: loading, validation, public paths
- Token lifecycle tests: create, verify, expire, revoke

Total: 75 tests passing

nora-registry/Cargo.toml

@@ -38,3 +38,10 @@ tar = "0.4"
 flate2 = "1.0"
 indicatif = "0.17"
 chrono = { version = "0.4", features = ["serde"] }
+thiserror = "2"
+tower_governor = "0.8"
+governor = "0.10"
+
+[dev-dependencies]
+tempfile = "3"
+wiremock = "0.6"