test(transcribe): WithTimeout hands the engine the job's language, as on the production path (#61)

The wrapper sits in front of both local engines; a fresh context there would send an auto
upload as language=sv and un-cancel the job, and no test noticed. Found by the PR #62 review.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/adapters/transcribe/timeout_test.go

@@ -102,3 +102,32 @@ func TestEnsemble_AHungEngineIsASoftFailureAndTheOtherEnginesTextIsUsed(t *testi
 	assert.Contains(t, got.Reconciliation.Reason, "timeout")
 	assert.False(t, errors.Is(err, context.DeadlineExceeded))
 }
+
+// WithTimeout sits in front of both local engines in production (cmd/tapir/uploads.go). It
+// must hand the engine the job's context, not a fresh one: the language and the
+// cancellation both travel on it (tapir#61).
+
+func TestWithTimeout_TheEngineStillReceivesTheLanguageOfTheJob(t *testing.T) {
+	for name, tt := range map[string]struct {
+		ctx       context.Context
+		wantField bool
+	}{
+		"auto leaves the field out": {domain.WithLanguage(context.Background(), domain.LangAuto), false},
+		"swedish sends sv":          {domain.WithLanguage(context.Background(), domain.LangSwedish), true},
+	} {
+		t.Run(name, func(t *testing.T) {
+			var got seen
+			srv := serve(t, 200, verboseJSON, &got)
+			b := transcribe.WithTimeout(transcribe.NewGateway(srv.URL+"/v1", "k", "iguana/kb-whisper", srv.Client()), time.Minute)
+
+			_, err := b.Transcribe(tt.ctx, wavFile(t, "RIFF-synthetic-pcm"))
+
+			require.NoError(t, err)
+			lang, present := got.fields["language"]
+			assert.Equal(t, tt.wantField, present)
+			if tt.wantField {
+				assert.Equal(t, "sv", lang)
+			}
+		})
+	}
+}