Ablation: pin gpt-5.5 @ ai.gahow.org (chat.completions); re-read token per arm

- Pin endpoint.model=gpt-5.5, base_url=https://ai.gahow.org/v1, wire_api=chat.completions
  in both ablation specs so both arms uniformly use the current ~/.codex model (the
  prior runs used the stale ai.prism.uno/gpt-5.4 that config.toml has since moved off).
- run_ablation_pair_d1.sh re-reads the codex token from auth.json right before each arm
  instead of capturing it once at launch (the stale-at-use capture 401'd naive 2/3).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

configs/examples/dash0_qwen27b_ablation_harness_on.json

@@ -168,7 +168,9 @@
     "max_history_trials": 8,
     "endpoint": {
       "provider": "codex",
-      "model": "gpt-5.4",
+      "model": "gpt-5.5",
+      "base_url": "https://ai.gahow.org/v1",
+      "wire_api": "chat.completions",
       "stream": true,
       "api_key_env": "OPENAI_API_KEY",
       "timeout_s": 180

configs/examples/dash0_qwen27b_ablation_naive_off.json

@@ -168,7 +168,9 @@
     "max_history_trials": 8,
     "endpoint": {
       "provider": "codex",
-      "model": "gpt-5.4",
+      "model": "gpt-5.5",
+      "base_url": "https://ai.gahow.org/v1",
+      "wire_api": "chat.completions",
       "stream": true,
       "api_key_env": "OPENAI_API_KEY",
       "timeout_s": 180

scripts/run_ablation_pair_d1.sh

@@ -5,19 +5,23 @@
 # window), per-probe Stop-A-consistent drain deadline. Harness stops early; naive
 # runs the full budget. Run from the repo root on dash1.
 set -u
-export OPENAI_API_KEY=$(python3 -c 'import json,pathlib;print(json.load(open(pathlib.Path.home()/".codex/auth.json"))["OPENAI_API_KEY"])')
+# Re-read the codex token from auth.json right before each arm (capturing it once at
+# launch goes stale during a long run -- that is what 401'd naive runs 2/3).
+read_key() { export OPENAI_API_KEY=$(python3 -c 'import json,pathlib;print(json.load(open(pathlib.Path.home()/".codex/auth.json"))["OPENAI_API_KEY"])'); }
 # codex config.toml points at a dash0-local proxy (127.0.0.1:11235); on dash1 the
 # LLM endpoint is reachable directly, so force a direct connection.
 export http_proxy= https_proxy= all_proxy= HTTP_PROXY= HTTPS_PROXY= ALL_PROXY= no_proxy='*'
 mkdir -p .aituner
 rm -rf .aituner/abl12-harness .aituner/abl12-naive .aituner/ABLATION12_DONE
 
+read_key
 echo "=== harness ON  (12-iter) start $(date -Is) ==="
 PYTHONPATH=src python3 -m aituner.cli study tune \
   --spec configs/examples/dash0_qwen27b_ablation_harness_on.json \
   --store-root .aituner/abl12-harness --max-trials 12 --skip-baseline > .aituner/abl12-harness.log 2>&1
 echo "=== harness ON  (12-iter) done  $(date -Is) ==="
 
+read_key
 echo "=== naive OFF   (12-iter) start $(date -Is) ==="
 PYTHONPATH=src python3 -m aituner.cli study tune \
   --spec configs/examples/dash0_qwen27b_ablation_naive_off.json \