diff --git a/internal/app/commands.go b/internal/app/commands.go
index f47759f..62fd0b6 100644
--- a/internal/app/commands.go
+++ b/internal/app/commands.go
@@ -51,8 +51,3 @@ func Execute(args []string, stdout, stderr io.Writer) int {
 func printUsage(w io.Writer) {
 	fmt.Fprintf(w, "Usage: narratio <%s>\n", strings.Join(supportedCommands, "|"))
 }
-
-func placeholder(out io.Writer, command string) error {
-	_, err := fmt.Fprintf(out, "narratio %s: not yet implemented\n", command)
-	return err
-}
diff --git a/internal/artifacts/s3.go b/internal/artifacts/s3.go
deleted file mode 100644
index ab9f0d1..0000000
--- a/internal/artifacts/s3.go
+++ /dev/null
@@ -1,57 +0,0 @@
-package artifacts
-
-import (
-	"fmt"
-	"os"
-)
-
-// S3Store is a placeholder for future remote artifact persistence support.
-type S3Store struct {
-	Bucket string
-	Prefix string
-}
-
-// SessionPathsFor is not implemented for S3-backed storage.
-func (s *S3Store) SessionPathsFor(_, _ string) SessionPaths {
-	return SessionPaths{}
-}
-
-// EnsureLayoutFor returns a not-yet-implemented error in the scaffold.
-func (s *S3Store) EnsureLayoutFor(_, _ string) (SessionPaths, error) {
-	return SessionPaths{}, fmt.Errorf("artifacts s3 ensure layout for campaign/session: not yet implemented")
-}
-
-// CopyInputFor returns a not-yet-implemented error in the scaffold.
-func (s *S3Store) CopyInputFor(_, _, _, _ string) (Ref, error) {
-	return Ref{}, fmt.Errorf("artifacts s3 copy input for campaign/session: not yet implemented")
-}
-
-// Exists returns a not-yet-implemented error in the scaffold.
-func (s *S3Store) Exists(_ string) (bool, error) {
-	return false, fmt.Errorf("artifacts s3 exists: not yet implemented")
-}
-
-// ExistsRef returns a not-yet-implemented error in the scaffold.
-func (s *S3Store) ExistsRef(_ Ref) (bool, error) {
-	return false, fmt.Errorf("artifacts s3 exists ref: not yet implemented")
-}
-
-// WriteFileAtomic returns a not-yet-implemented error in the scaffold.
-func (s *S3Store) WriteFileAtomic(_ string, _ []byte, _ os.FileMode) error {
-	return fmt.Errorf("artifacts s3 write file atomic: not yet implemented")
-}
-
-// Checksum returns a not-yet-implemented error in the scaffold.
-func (s *S3Store) Checksum(_ string) (string, error) {
-	return "", fmt.Errorf("artifacts s3 checksum: not yet implemented")
-}
-
-// AcquireSessionLockFor returns a not-yet-implemented error in the scaffold.
-func (s *S3Store) AcquireSessionLockFor(_, _ string) (*LockHandle, error) {
-	return nil, fmt.Errorf("artifacts s3 acquire lock for campaign/session: not yet implemented")
-}
-
-// ReleaseSessionLock returns a not-yet-implemented error in the scaffold.
-func (s *S3Store) ReleaseSessionLock(_ *LockHandle) error {
-	return fmt.Errorf("artifacts s3 release lock: not yet implemented")
-}
diff --git a/internal/contracts/artifact.go b/internal/contracts/artifact.go
deleted file mode 100644
index a2966b6..0000000
--- a/internal/contracts/artifact.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package contracts
-
-// ArtifactResult is a placeholder generated artifact contract.
-type ArtifactResult struct {
-	Schema string `json:"schema"`
-	Path   string `json:"path"`
-}
diff --git a/internal/contracts/session.go b/internal/contracts/session.go
deleted file mode 100644
index 5c3bb46..0000000
--- a/internal/contracts/session.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package contracts
-
-// SessionManifest is a placeholder durable session-run contract.
-type SessionManifest struct {
-	Schema    string `json:"schema"`
-	SessionID string `json:"session_id"`
-}
diff --git a/internal/contracts/transcript.go b/internal/contracts/transcript.go
deleted file mode 100644
index 9c33036..0000000
--- a/internal/contracts/transcript.go
+++ /dev/null
@@ -1,19 +0,0 @@
-package contracts
-
-// SpeakerTranscript is a placeholder transcription artifact contract.
-type SpeakerTranscript struct {
-	Schema    string `json:"schema"`
-	SessionID string `json:"session_id"`
-}
-
-// CanonicalTranscript is a placeholder merged transcript contract.
-type CanonicalTranscript struct {
-	Schema    string `json:"schema"`
-	SessionID string `json:"session_id"`
-}
-
-// ProcessedTranscript is a placeholder polished transcript contract.
-type ProcessedTranscript struct {
-	Schema    string `json:"schema"`
-	SessionID string `json:"session_id"`
-}