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_memory_config.py

@@ -45,7 +45,7 @@ def test_memory_defaults():
     assert cfg.memory.transcript.xml_scrub_depth == 1
     # Ready chunks replace their turns only once the
     # operator's measured context reaches budget*start_ratio.
-    assert cfg.memory.chunking.min_steps == 3
+    assert cfg.memory.chunking.min_steps == 6
     assert cfg.memory.transcript.image_scrub_depth_relaxed == 6
     assert cfg.memory.transcript.start_ratio == 0.35
     assert cfg.memory.transcript.soft_ratio == 0.7