Add decode-only study mode support

configs/examples/dash0_qwen235b_decode_thinking_baseline.json

@@ -0,0 +1,13 @@
+{
+  "observation": "This is the decode-only baseline directly aligned with run_qwen235b_decode.sh, including DecodeBenchConnector and the internal qwen3-235b launch shape.",
+  "diagnosis": "A baseline measurement is required before proposing decode-only throughput changes. Preserve all current envs and flags to establish the first feasible sampling_u/request_rate point under the TPOT-only SLO.",
+  "config_patch": {
+    "env_patch": {},
+    "flag_patch": {}
+  },
+  "expected_effects": [
+    "Establish a launch-safe baseline for decode-only TPOT tuning",
+    "Seed later trials from the first feasible sampling_u if one exists"
+  ],
+  "why_not_previous_failures": "No previous failures in this study."
+}