feat(storage-minio): initial implementation — MinIO/S3 object storage with lifecycle (v1.0.0)

Introduces code.nochebuena.dev/einherjar/storage-minio — the object storage
starter for the Einherjar framework. Absorbs the minio package from micro-lib,
replacing fmt.Errorf wrapping with core/xerrors.

Interfaces (CT-6: one TypeSpec per file):
- Provider — PutObject, RemoveObject, GetObject, PresignedGetObject, HandleError
- Component — lifecycle.Component + observability.Checkable + Provider + Native()

Implementation:
- New(logger, cfg) Component — client not created until OnInit
- OnInit: minio.New with credentials and transport; bucket existence check
- OnStart: BucketExists PING; logs "minio: connected"
- OnStop: logs "minio: closing client" (minio-go is stateless; no explicit close)
- HealthCheck: BucketExists check; Priority LevelCritical
- Native() *miniogo.Client — escape hatch for operations not in Provider
- HandleError: maps minio-go errors to xerrors (NotFound, AlreadyExists, Internal)

Config (EINHERJAR_MINIO_* env vars):
  Endpoint(required), AccessKey(required), SecretKey(required),
  Bucket(required), UseSSL(false), Region(us-east-1)

- Component interface embeds observability.Identifiable; identifiable.go implements
  ModulePath and ModuleVersion via runtime/debug.ReadBuildInfo() — prints in launcher banner

identifiable.go

@@ -0,0 +1,21 @@
+package minio
+
+import "runtime/debug"
+
+const modulePath = "code.nochebuena.dev/einherjar/storage-minio"
+
+func (m *minioImpl) ModulePath() string { return modulePath }
+
+func (m *minioImpl) ModuleVersion() string {
+	if info, ok := debug.ReadBuildInfo(); ok {
+		for _, dep := range info.Deps {
+			if dep.Path == modulePath {
+				return dep.Version
+			}
+		}
+		if info.Main.Path == modulePath {
+			return info.Main.Version
+		}
+	}
+	return "(devel)"
+}