🎨 Palette: Add actionable instruction to checkpoint empty state

.Jules/palette.md

@@ -5,3 +5,7 @@
 ## 2024-05-24 - CLI Output Scannability and Human-Readability
 **Learning:** In text-based CLI menus, using internal identifiers (like `lesson-1`) and verbose status strings (like `pending` or `completed`) makes lists hard to scan and feels too technical.
 **Action:** When displaying lists of items with states, use familiar visual symbols (like `[x]` vs `[ ]`) and human-readable titles (like "Variables") to improve scannability and create a more friendly, intuitive interface.
+
+## 2024-05-25 - Actionable Empty States
+**Learning:** In CLI applications, empty states (e.g., "No items found") can leave users at a dead end, unsure of what to do next.
+**Action:** Always provide actionable instructions or commands in empty state messages to guide the user on how to create the missing resource.

src/python_learning_orchestrated/cli.py

@@ -223,7 +223,9 @@ def main(
         if args.checkpoint_command == "list":
             checkpoints = checkpoint_store.list_checkpoints()
             if not checkpoints:
-                output_fn("No checkpoints found.")
+                output_fn(
+                    "No checkpoints found. Create one using 'checkpoint create <name>'."
+                )
                 return
             output_fn(f"Checkpoints ({len(checkpoints)}):")
             for checkpoint in checkpoints:

tests/test_cli_smoke.py

@@ -91,6 +91,14 @@ def test_cli_export_and_import_progress_commands(tmp_path, capsys) -> None:
     assert len(session_payload["attempts"]) == 1
 
 
+def test_cli_checkpoint_list_empty(capsys) -> None:
+    main(["checkpoint", "list"])
+    output = capsys.readouterr().out
+    assert (
+        "No checkpoints found. Create one using 'checkpoint create <name>'." in output
+    )
+
+
 def test_cli_checkpoint_create_and_list(tmp_path, capsys, monkeypatch) -> None:
     session_file = tmp_path / "session.json"
     checkpoint_dir = tmp_path / "checkpoints"