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.

artemis/plugins/models.py

@@ -229,9 +229,22 @@ class PluginCallResult(PluginModel):
     def text(self) -> str:
         import json
 
-        parts = [str(block["text"]) for block in self.content if block.get("type") == "text"]
+        parts = list(
+            dict.fromkeys(
+                str(block["text"]) for block in self.content if block.get("type") == "text"
+            )
+        )
         if self.structured_content is not None:
-            parts.append(json.dumps(self.structured_content, ensure_ascii=False))
+            # MCP commonly returns the same accessibility tree in both channels.
+            # Keep one exact copy, without changing the persisted raw response.
+            visible_text = "\n".join(parts)
+            structured = {
+                key: "[identical text already included above]"
+                if isinstance(value, str) and len(value) >= 256 and value in visible_text
+                else value
+                for key, value in self.structured_content.items()
+            }
+            parts.append(json.dumps(structured, ensure_ascii=False))
         if self.message:
             parts.append(self.message)
         return "\n".join(parts) or "工具已返回；请根据证据判断业务结果。"