feat: add official Codex skill and harden task execution

Install and update artemis-use with task diagnostics and plugin guidance. Preserve cross-device file receipts, review canonical reports, guard stage transitions and reduce small history summaries. Improve exploration lifecycle, request recovery and browser live connections.

tests/unit/test_cli.py

@@ -249,7 +249,7 @@ def test_cli_mcp_install_codex_preserves_config_and_is_idempotent(tmp_path, monk
     config_file.write_text(
         'model = "test-model"\n\n'
         '[mcp_servers.existing]\ncommand = "echo"\n\n'
-        '[mcp_servers.artemis]\ncommand = "old-command"\n',
+        '[mcp_servers.artemis]\ncommand = "old-command"\nargs = ["-m", "mcp_server"]\n',
         encoding="utf-8",
     )
 
@@ -283,12 +283,12 @@ def test_cli_mcp_install_codex_preserves_config_and_is_idempotent(tmp_path, monk
         "mobile_export_report",
     ]
     assert data["mcp_servers"]["artemis"]["env"]["PYTHONPATH"] == str(tmp_path)
-    assert config_text.count("# BEGIN ARTEMIS MCP CONFIG") == 1
+    assert config_text.count("[mcp_servers.artemis]") == 1
 
     agents_file = codex_dir / "AGENTS.md"
-    agents_text = agents_file.read_text(encoding="utf-8")
-    assert "Mobile Testing Mindset" in agents_text
-    assert agents_text.count("<!-- BEGIN ARTEMIS MOBILE TESTING RULES -->") == 1
+    assert not agents_file.exists()
+    skill_file = tmp_path / ".agents/skills/artemis-use/SKILL.md"
+    assert "name: artemis-use" in skill_file.read_text(encoding="utf-8")
 
 
 def test_cli_restart_help():