agentic(trace-source): default non-DSv4 to v6 (060226) corpus

resolve_trace_source() now picks a model-prefix-aware default:

  MODEL_PREFIX == dsv4  -> semianalysis_cc_traces_weka_with_subagents
                           (052726, the v5 baseline, unchanged for
                           continuity with prior DSv4 published runs)
  everything else       -> semianalysis_cc_traces_weka_with_subagents_060226
                           (060226, newer v6 corpus with fresher CC
                           recording windows)

WEKA_LOADER_OVERRIDE still wins. Allowed values widened from the
two 052726 loaders to all four:

  semianalysis_cc_traces_weka_with_subagents          (052726)
  semianalysis_cc_traces_weka_with_subagents_256k     (052726-256k)
  semianalysis_cc_traces_weka_with_subagents_060226   (060226)
  semianalysis_cc_traces_weka_with_subagents_060226_256k (060226-256k)

Bumps utils/aiperf submodule to de3ad1c1, which registers the two
060226 plugin entries those new loader names resolve through.

The pre-cache log line now also includes MODEL_PREFIX so it's obvious
in CI which default fired.

Signed-off-by: Cam Quilici <cameron@semianalysis.com>

Author: camatsemianalysis

benchmarks/benchmark_lib.sh

@@ -924,8 +924,19 @@ resolve_trace_source() {
     # public-dataset loader names allowed by the inferencex-agentx-mvp
     # scenario. Used by recipes whose servers have non-default context
     # caps (e.g. minimaxm2.5 at max_model_len ~256k can't replay the
-    # unfiltered 052726 corpus and switches to the 256k-capped variant).
-    local loader="${WEKA_LOADER_OVERRIDE:-semianalysis_cc_traces_weka_with_subagents}"
+    # unfiltered corpus and switches to the 256k-capped variant), or
+    # by recipes that want to pin a specific corpus generation rather
+    # than ride the model-prefix-aware default below.
+    #
+    # Default (no override) is model-prefix-aware:
+    #   DSv4 recipes      -> 052726 (v5 corpus, the original baseline)
+    #   everything else   -> 060226 (v6 corpus, newer CC versions)
+    # DSv4 stays on 052726 for continuity with prior published baselines.
+    local default_loader="semianalysis_cc_traces_weka_with_subagents_060226"
+    if [[ "${MODEL_PREFIX:-}" == "dsv4" ]]; then
+        default_loader="semianalysis_cc_traces_weka_with_subagents"
+    fi
+    local loader="${WEKA_LOADER_OVERRIDE:-$default_loader}"
     local dataset
     case "$loader" in
         semianalysis_cc_traces_weka_with_subagents)
@@ -934,13 +945,19 @@ resolve_trace_source() {
         semianalysis_cc_traces_weka_with_subagents_256k)
             dataset="semianalysisai/cc-traces-weka-with-subagents-052726-256k"
             ;;
+        semianalysis_cc_traces_weka_with_subagents_060226)
+            dataset="semianalysisai/cc-traces-weka-with-subagents-060226"
+            ;;
+        semianalysis_cc_traces_weka_with_subagents_060226_256k)
+            dataset="semianalysisai/cc-traces-weka-with-subagents-060226-256k"
+            ;;
         *)
-            echo "Error: unknown WEKA_LOADER_OVERRIDE='$loader'. Allowed: semianalysis_cc_traces_weka_with_subagents, semianalysis_cc_traces_weka_with_subagents_256k" >&2
+            echo "Error: unknown WEKA_LOADER_OVERRIDE='$loader'. Allowed: semianalysis_cc_traces_weka_with_subagents, semianalysis_cc_traces_weka_with_subagents_256k, semianalysis_cc_traces_weka_with_subagents_060226, semianalysis_cc_traces_weka_with_subagents_060226_256k" >&2
             exit 1
             ;;
     esac
     TRACE_SOURCE_FLAG="--public-dataset $loader"
-    echo "Loading traces via aiperf public-dataset: $loader ($dataset)"
+    echo "Loading traces via aiperf public-dataset: $loader ($dataset) [MODEL_PREFIX=${MODEL_PREFIX:-unset}]"
     # Pre-download the dataset into the shared HF_HUB_CACHE (same mount used
     # for model weights) so subsequent runs read from cache instead of
     # re-downloading every job.