test: fix test failures from refactored cron and context builder

- test_context_prompt_cache: Update test to reflect merged runtime
  context and user message (commit ad99d5a merged them into one)
- Remove test_cron_commands.py: cron add CLI command was removed
  in commit c05cb2e (unified scheduling via cron tool)

tests/test_context_prompt_cache.py

@@ -40,7 +40,7 @@ def test_system_prompt_stays_stable_when_clock_changes(tmp_path, monkeypatch) ->
 
 
 def test_runtime_context_is_separate_untrusted_user_message(tmp_path) -> None:
-    """Runtime metadata should be a separate user message before the actual user message."""
+    """Runtime metadata should be merged with the user message."""
     workspace = _make_workspace(tmp_path)
     builder = ContextBuilder(workspace)
 
@@ -55,11 +55,12 @@ def test_runtime_context_is_separate_untrusted_user_message(tmp_path) -> None:
     assert "## Current Session" not in messages[0]["content"]
 
     assert len(messages) == 2
+    # Runtime context is now merged with user message into a single message
     assert messages[-1]["role"] == "user"
-    runtime_content = messages[-1]["content"]
-    assert isinstance(runtime_content, str)
-    assert ContextBuilder._RUNTIME_CONTEXT_TAG in runtime_content
-    assert "Current Time:" in runtime_content
-    assert "Channel: cli" in runtime_content
-    assert "Chat ID: direct" in runtime_content
-    assert "Return exactly: OK" in runtime_content
+    user_content = messages[-1]["content"]
+    assert isinstance(user_content, str)
+    assert ContextBuilder._RUNTIME_CONTEXT_TAG in user_content
+    assert "Current Time:" in user_content
+    assert "Channel: cli" in user_content
+    assert "Chat ID: direct" in user_content
+    assert "Return exactly: OK" in user_content