fix(session): preserve history across storage relocation

Co-authored-by: lmzopq <1646888+lmzopq@users.noreply.github.com>

nanobot/cli/commands.py

@@ -440,6 +440,44 @@ app.add_typer(
 app.command(name="agent")(agent)
 
 
+# ============================================================================
+# Session Commands
+# ============================================================================
+
+
+sessions_app = typer.Typer(help="Manage persisted session history")
+app.add_typer(sessions_app, name="sessions")
+
+
+@sessions_app.command("restore-workspace")
+def sessions_restore_workspace(
+    config: str | None = typer.Option(None, "--config", "-c", help="Path to config file"),
+    workspace: str | None = typer.Option(None, "--workspace", "-w", help="Workspace directory"),
+) -> None:
+    """Copy sessions back into the workspace before downgrading nanobot."""
+    from nanobot.session.manager import SessionManager
+
+    runtime_config = _load_runtime_config(config, workspace)
+    data_dir = runtime_config.runtime_data_dir
+    manager = SessionManager(
+        runtime_config.workspace_path,
+        sessions_root=data_dir / "sessions" if data_dir is not None else None,
+    )
+    result = manager.restore_sessions_to_workspace()
+    console.print(
+        f"Restored {result.restored} session file(s) to "
+        f"{escape(str(runtime_config.workspace_path / 'sessions'))}; "
+        f"{result.unchanged} already matched."
+    )
+    if result.conflicts:
+        console.print(
+            "[red]Rollback is incomplete: existing or invalid files require manual review.[/red]"
+        )
+        for path in result.conflicts:
+            console.print(Text(f"- {path}", style="red"))
+        raise typer.Exit(1)
+
+
 # ============================================================================
 # Channel Commands
 # ============================================================================