Implement prepare stage input resolution

internal/app/commands_test.go

@@ -172,6 +172,11 @@ inputs:
 		t.Fatalf("write session config: %v", err)
 	}
 
+	mustWriteTestFile(t, filepath.Join(dir, "speakers.yml"), "alice: alice.flac\n")
+	mustWriteTestFile(t, filepath.Join(dir, "autocorrect.yml"), "[]\n")
+	mustWriteTestFile(t, filepath.Join(dir, "glossary.yml"), "[]\n")
+	mustWriteTestFile(t, filepath.Join(dir, "audio", "alice.flac"), "audio-bytes")
+
 	return pipelinePath, sessionPath
 }
 
@@ -189,3 +194,13 @@ func writeManifestPathForExecute(t *testing.T) string {
 
 	return path
 }
+
+func mustWriteTestFile(t *testing.T, path, contents string) {
+	t.Helper()
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		t.Fatalf("mkdir %q: %v", path, err)
+	}
+	if err := os.WriteFile(path, []byte(contents), 0o644); err != nil {
+		t.Fatalf("write %q: %v", path, err)
+	}
+}