internal/pkg: append user-facing name in messages

This makes verbose messages much more useful.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/net.go

@@ -3,8 +3,10 @@ package pkg
 import (
 	"context"
 	"crypto/sha512"
+	"fmt"
 	"io"
 	"net/http"
+	"path"
 	"sync"
 )
 
@@ -30,6 +32,7 @@ type httpArtifact struct {
 }
 
 var _ KnownChecksum = new(httpArtifact)
+var _ fmt.Stringer = new(httpArtifact)
 
 // NewHTTPGet returns a new [File] backed by the supplied client. A GET request
 // is set up for url. If c is nil, [http.DefaultClient] is used instead.
@@ -57,6 +60,9 @@ func (a *httpArtifact) Dependencies() []Artifact { return nil }
 // Checksum returns the caller-supplied checksum.
 func (a *httpArtifact) Checksum() Checksum { return a.checksum }
 
+// String returns [path.Base] over the backing url.
+func (a *httpArtifact) String() string { return path.Base(a.url) }
+
 // ResponseStatusError is returned for a response returned by an [http.Client]
 // with a status code other than [http.StatusOK].
 type ResponseStatusError int