Reduce ablation probe budget to 3 per trial for tractability

First TP1 baseline probe under scale=0.2 ran ~6min (severe overload, 260
preemptions on the lighter half of the trace; TP1 is decode-bound and the
arrival-lag early-stop does not cut a decode-drain-bound probe). Cut
search.max_probes 5->3 to bound binary-search steps per trial. Caps stay
at elapsed=180/lag=30. Both configs still differ only in use_harness +
study_id.

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

configs/examples/dash0_qwen27b_ablation_harness_on.json

@@ -159,7 +159,7 @@
     "low": 0.0,
     "high": 0.25,
     "tolerance": 0.001,
-    "max_probes": 5,
+    "max_probes": 3,
     "sample_seed": 20260325,
     "inherit_incumbent_floor": true
   },

configs/examples/dash0_qwen27b_ablation_naive_off.json

@@ -159,7 +159,7 @@
     "low": 0.0,
     "high": 0.25,
     "tolerance": 0.001,
-    "max_probes": 5,
+    "max_probes": 3,
     "sample_seed": 20260325,
     "inherit_incumbent_floor": true
   },