fix: clean selection file, fix Node.js Dockerfile conflict, run+promote DOE rebalance batch

- Remove 20 stale entries from selected_benchmark_tasks.json for tasks
  moved to benchmarks/backups/*_doe_trim/ during MCP-unique DOE shrink
  (390 → 370: 150 SDLC + 220 MCP-unique)
- Add task_dir field to mcp_doe_rebalance_newruns.json for run_selected_tasks.sh
- Fix Dockerfile for ccx-migration-276 and ccx-vuln-remed-281: remove
  nodejs/npm apt packages that conflict with cloned node--v22.13.0
- All 20 DOE rebalance tasks ran (40 agent runs), 38/40 succeeded,
  2 errored baselines fixed and rerun successfully
- 6 batches promoted to runs/official/ (247 runs, 1315 scored tasks)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sjarmak

benchmarks/ccb_mcp_migration/ccx-migration-276/environment/Dockerfile

@@ -8,7 +8,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     ca-certificates \
     curl \
     python3 \
-    nodejs npm \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /workspace

benchmarks/ccb_mcp_security/ccx-vuln-remed-281/environment/Dockerfile

@@ -8,7 +8,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     ca-certificates \
     curl \
     python3 \
-    nodejs npm \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /workspace

configs/mcp_doe_rebalance_newruns.json

@@ -0,0 +1,133 @@
+{
+  "metadata": {
+    "description": "DOE rebalance: 13 scaffolded tasks (IDs 272-284) + 7 promoted onboarding tasks \u2014 first paired runs",
+    "generated": "2026-03-01",
+    "note": "13 scaffolded tasks have zero runs. 7 promoted onboarding tasks have 2-6 historical runs but need coverage under current DOE allocation."
+  },
+  "methodology": "first_result",
+  "statistics": {
+    "total_tasks": 20
+  },
+  "tasks": [
+    {
+      "task_id": "ccx-dep-trace-272",
+      "suite": "ccb_mcp_crossrepo_tracing",
+      "benchmark": "ccb_mcp_crossrepo_tracing",
+      "task_dir": "ccb_mcp_crossrepo_tracing/ccx-dep-trace-272"
+    },
+    {
+      "task_id": "ccx-dep-trace-273",
+      "suite": "ccb_mcp_crossrepo_tracing",
+      "benchmark": "ccb_mcp_crossrepo_tracing",
+      "task_dir": "ccb_mcp_crossrepo_tracing/ccx-dep-trace-273"
+    },
+    {
+      "task_id": "ccx-migration-274",
+      "suite": "ccb_mcp_migration",
+      "benchmark": "ccb_mcp_migration",
+      "task_dir": "ccb_mcp_migration/ccx-migration-274"
+    },
+    {
+      "task_id": "ccx-migration-275",
+      "suite": "ccb_mcp_migration",
+      "benchmark": "ccb_mcp_migration",
+      "task_dir": "ccb_mcp_migration/ccx-migration-275"
+    },
+    {
+      "task_id": "ccx-migration-276",
+      "suite": "ccb_mcp_migration",
+      "benchmark": "ccb_mcp_migration",
+      "task_dir": "ccb_mcp_migration/ccx-migration-276"
+    },
+    {
+      "task_id": "ccx-migration-277",
+      "suite": "ccb_mcp_migration",
+      "benchmark": "ccb_mcp_migration",
+      "task_dir": "ccb_mcp_migration/ccx-migration-277"
+    },
+    {
+      "task_id": "ccx-migration-278",
+      "suite": "ccb_mcp_migration",
+      "benchmark": "ccb_mcp_migration",
+      "task_dir": "ccb_mcp_migration/ccx-migration-278"
+    },
+    {
+      "task_id": "ccx-migration-279",
+      "suite": "ccb_mcp_migration",
+      "benchmark": "ccb_mcp_migration",
+      "task_dir": "ccb_mcp_migration/ccx-migration-279"
+    },
+    {
+      "task_id": "ccx-onboard-280",
+      "suite": "ccb_mcp_onboarding",
+      "benchmark": "ccb_mcp_onboarding",
+      "task_dir": "ccb_mcp_onboarding/ccx-onboard-280"
+    },
+    {
+      "task_id": "ccx-vuln-remed-281",
+      "suite": "ccb_mcp_security",
+      "benchmark": "ccb_mcp_security",
+      "task_dir": "ccb_mcp_security/ccx-vuln-remed-281"
+    },
+    {
+      "task_id": "ccx-vuln-remed-282",
+      "suite": "ccb_mcp_security",
+      "benchmark": "ccb_mcp_security",
+      "task_dir": "ccb_mcp_security/ccx-vuln-remed-282"
+    },
+    {
+      "task_id": "ccx-vuln-remed-283",
+      "suite": "ccb_mcp_security",
+      "benchmark": "ccb_mcp_security",
+      "task_dir": "ccb_mcp_security/ccx-vuln-remed-283"
+    },
+    {
+      "task_id": "ccx-vuln-remed-284",
+      "suite": "ccb_mcp_security",
+      "benchmark": "ccb_mcp_security",
+      "task_dir": "ccb_mcp_security/ccx-vuln-remed-284"
+    },
+    {
+      "task_id": "ccx-explore-042-ds",
+      "suite": "ccb_mcp_onboarding",
+      "benchmark": "ccb_mcp_onboarding",
+      "task_dir": "ccb_mcp_onboarding/ccx-explore-042-ds"
+    },
+    {
+      "task_id": "ccx-onboard-050-ds",
+      "suite": "ccb_mcp_onboarding",
+      "benchmark": "ccb_mcp_onboarding",
+      "task_dir": "ccb_mcp_onboarding/ccx-onboard-050-ds"
+    },
+    {
+      "task_id": "ccx-onboard-search-210",
+      "suite": "ccb_mcp_onboarding",
+      "benchmark": "ccb_mcp_onboarding",
+      "task_dir": "ccb_mcp_onboarding/ccx-onboard-search-210"
+    },
+    {
+      "task_id": "ccx-onboard-search-211",
+      "suite": "ccb_mcp_onboarding",
+      "benchmark": "ccb_mcp_onboarding",
+      "task_dir": "ccb_mcp_onboarding/ccx-onboard-search-211"
+    },
+    {
+      "task_id": "ccx-onboard-search-212",
+      "suite": "ccb_mcp_onboarding",
+      "benchmark": "ccb_mcp_onboarding",
+      "task_dir": "ccb_mcp_onboarding/ccx-onboard-search-212"
+    },
+    {
+      "task_id": "ccx-onboard-search-213",
+      "suite": "ccb_mcp_onboarding",
+      "benchmark": "ccb_mcp_onboarding",
+      "task_dir": "ccb_mcp_onboarding/ccx-onboard-search-213"
+    },
+    {
+      "task_id": "ccx-onboard-search-214",
+      "suite": "ccb_mcp_onboarding",
+      "benchmark": "ccb_mcp_onboarding",
+      "task_dir": "ccb_mcp_onboarding/ccx-onboard-search-214"
+    }
+  ]
+}