Improve crewai run startup UX (#6297)

Remove redundant startup logs from `crewai run` and make the legacy flow
command warning actionable.

- Stop printing `Running the Flow` and `Running the Crew` before project
  execution.
- Stop printing the redundant `Flow started with ID: ...` line while
  preserving flow lifecycle event emission.
- Replace Click's generic `kickoff` deprecation warning with a clearer
  message that tells users to use `crewai run`.

lib/cli/tests/test_cli.py

@@ -190,7 +190,10 @@ def test_flow_kickoff_is_deprecated_and_uses_run_path(run_crew, runner):
         definition=None,
         inputs=None,
     )
-    assert "DeprecationWarning" in result.output
+    assert (
+        "The command 'crewai flow kickoff' is deprecated. Use 'crewai run' instead."
+        in result.output
+    )
 
 
 @mock.patch("crewai_cli.create_json_crew.create_json_crew")

lib/cli/tests/test_create_flow.py

@@ -31,5 +31,5 @@ def test_create_flow_declarative_project_can_run(
     result = CliRunner().invoke(crewai, ["run"], env={"UV_RUN_RECURSION_DEPTH": "1"})
 
     assert result.exit_code == 0
-    assert "Running the Flow" in result.output
+    assert "Running the Flow" not in result.output
     assert "AI agents" in result.output

lib/cli/tests/test_flow_commands.py

@@ -44,8 +44,12 @@ def test_flow_kickoff_runs_configured_declarative_definition(
     result = CliRunner().invoke(flow_run)
 
     assert result.exit_code == 0
-    assert "DeprecationWarning" in result.output
-    assert "Running the Flow\nAI\n" in result.output
+    assert (
+        "The command 'crewai flow kickoff' is deprecated. Use 'crewai run' instead."
+        in result.output
+    )
+    assert "AI\n" in result.output
+    assert "Running the Flow" not in result.output
 
 
 def test_plot_flow_runs_configured_declarative_definition(

lib/cli/tests/test_run_crew.py

@@ -622,7 +622,7 @@ def test_run_crew_runs_classic_crew_project(monkeypatch, capsys):
 
     run_crew_module.run_crew(trained_agents_file="trained.pkl")
 
-    assert capsys.readouterr().out == "Running the Crew\n"
+    assert capsys.readouterr().out == ""
     assert calls == [
         (
             "run_crew",
@@ -648,7 +648,7 @@ def test_run_crew_runs_python_flow_project(monkeypatch, capsys):
 
     run_crew_module.run_crew()
 
-    assert capsys.readouterr().out == "Running the Flow\n"
+    assert capsys.readouterr().out == ""
     assert calls == [("kickoff", {"entity_type": "flow"})]
 
 
@@ -694,5 +694,5 @@ def test_run_crew_runs_configured_declarative_flow_project(monkeypatch, capsys):
 
     run_crew_module.run_crew()
 
-    assert capsys.readouterr().out == "Running the Flow\n"
+    assert capsys.readouterr().out == ""
     assert calls == [("flow.yaml", None)]