feat: add guided exploration and share user-started MCP backend

config/artemis.jsonc

@@ -34,6 +34,13 @@
     "checker": {}
   },
   "agent": {
+    "exploration": {
+      "model": "${env:ARTEMIS_EXPLORATION_MODEL:-gpt-6.1-sol}",
+      "reasoning_effort": "${env:ARTEMIS_EXPLORATION_REASONING_EFFORT:-high}",
+      "timeout_seconds": "${env:ARTEMIS_EXPLORATION_TIMEOUT_SECONDS:-1800}",
+      "demonstration_timeout_seconds": "${env:ARTEMIS_DEMONSTRATION_TIMEOUT_SECONDS:-900}",
+      "demonstration_warning_seconds": 60
+    },
     // 留档录像参数，默认从 ARTEMIS_RECORDING_CONFIG 读取；这里可单独覆盖。
     "recording": {},
     "screenshot": {