spark: generate timestamped report artifact

wizard-work/spark/report.json

@@ -1,17 +1,6 @@
 {
-  "timestamp": "2026-10-15T19:09:31.811751+00:00",
-  "hostname": "WorkBench",
-  "platform": "Linux-6.8.0-71-generic-x86_64-with-glibc2.39",
-  "python_version": "3.14.7",
-  "working_directory": "/root",
-  "user": "root",
-  "home": "/root",
-  "environment_vars": {
-    "SHELL": "/usr/bin/bash",
-    "PWD": "/root",
-    "HOME": "/root",
-    "LANG": "C.UTF-8",
-    "USER": "root",
-    "PATH": "/root/.local/bin:/root/.local/bin:/usr/local/lib/hermes-agent/.hermes/bin:/root/.hermes/installs/76f6e7e5145b5f39/environments/c69072dfe8ac406e9de1c475ac57f334/venv/bin:/usr/local/lib/hermes-agent/venv/bin:/usr/local/lib/hermes-agent/node_modules/.bin:/root/.hermes/node/bin:/root/.hermes/node:/root/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/root/.hermes/profiles/spark/bin:/root/.hermes/tools/python-3.14.7+20260901-linux-x64/bin:/root/.hermes/tools/agent-browser-0.26.0-linux-x64/bin:/root/.hermes/tools/cua-driver-0.21.0-linux-x64:/root/.hermes/tools/ffmpeg-9.0.1-linux-x64/bin:/root/.hermes/tools/npm-12.0.2-linux-x64/bin:/root/.hermes/tools/node-26.7.0-linux-x64/bin:/root/.hermes/tools/ripgrep-15.2.0-linux-x64:/snap/bin"
-  }
+  "artifact": "spark_report",
+  "generated_at": "2026-10-30T22:47:50.150983Z",
+  "status": "success",
+  "message": "Report generated by spark snippet"
 }