Engine-state ablation: full sweep harness + results

Real-time engine state is NOT the routing lever. Across 6 policies × es0/es1,
real state reshuffles 44-76% of decisions but never beats the champion
(unified+A+B, p90 7.62s). The effect's SIGN is set by reactivity: one-shot
placement (sticky) HELPS -26%; per-request affinity-dominated is a wash;
per-request pure-load (lmetric +17%, load_only +27%) HURTS via herding (stale
shadow was a dampener). Feed verified fresh (median 25ms, <=92ms during
prefills). Prior shadow-state results stand. ES_ABLATION_RESULTS.md has the
table + mechanism; run_full_ablation.sh / fresh_sampler.py / cmp_es.py are the
harness.

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

microbench/connector_tax/layerwise/run_full_ablation.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+# Full engine-state ablation sweep on dash1 (sequential; shared-venv patch
+# can't be parallelized). Waits for the in-flight champion es1 to finish, then
+# runs the remaining policies as matched es0/es1 pairs. Each es1 cell gets a
+# freshness sampler (age_s = now - state.ts) written to cpfs.
+#
+# Champion: es0 already done (v3trace_unified_AB_es0_20260528_1633),
+#           es1 in flight (launch_es1.sh) -> reused, not re-run here.
+set -uo pipefail
+PROJ=/home/admin/cpfs/wjh/agentic-kv
+LWDIR=$PROJ/microbench/connector_tax/layerwise
+R=$LWDIR/run_v3_trace.sh
+SAMPLER=$LWDIR/fresh_sampler.py
+PY=$PROJ/.venv/bin/python
+AB="--overload-factor 1.3 --lmetric-decode-weight 0.01"
+PROG=$PROJ/outputs/abl_full.progress
+MASTERDONE=$PROJ/outputs/abl_full.done
+rm -f "$MASTERDONE"
+
+echo "[driver] $(date) waiting for champion es1 (abl_unified_AB_es1.done) ..." >> "$PROG"
+while [ ! -f "$PROJ/outputs/abl_unified_AB_es1.done" ]; do sleep 30; done
+echo "[driver] $(date) champion es1 done -> starting sweep" >> "$PROG"
+
+# TAG | POLICY | MODE | AB(yes=AB) | ES
+CONFIGS=(
+ "lmetric_es0|lmetric|baseline||0"
+ "lmetric_es1|lmetric|baseline||1"
+ "load_only_es0|load_only|baseline||0"
+ "load_only_es1|load_only|baseline||1"
+ "sticky_es0|sticky|baseline||0"
+ "sticky_es1|sticky|baseline||1"
+ "v3_AB_lw_es0|unified_v3|layerwise|AB|0"
+ "v3_AB_lw_es1|unified_v3|layerwise|AB|1"
+ "ukvboth_AB_es0|unified_kv_both|baseline|AB|0"
+ "ukvboth_AB_es1|unified_kv_both|baseline|AB|1"
+)
+
+for cfg in "${CONFIGS[@]}"; do
+  IFS='|' read -r tag policy mode ab es <<< "$cfg"
+  abf=""; [ "$ab" = "AB" ] && abf="$AB"
+  esdir=/dev/shm/agentic_engine_state_${tag}
+  fresh=$PROJ/outputs/abl_${tag}.freshness.jsonl
+  rl=$PROJ/outputs/abl_${tag}.runlog
+  celldone=$PROJ/outputs/abl_${tag}.celldone
+  rm -f "$fresh" "$celldone"
+  echo "[driver] $(date) START $tag (policy=$policy mode=$mode ab=$ab es=$es)" >> "$PROG"
+
+  sp=""
+  if [ "$es" = "1" ]; then
+    nohup "$PY" "$SAMPLER" "$esdir" "$fresh" "$celldone" >/dev/null 2>&1 &
+    sp=$!
+  fi
+
+  TAG="$tag" POLICY="$policy" MODE="$mode" AB_FLAGS="$abf" ES="$es" \
+    bash "$R" > "$rl" 2>&1
+  ec=$?
+
+  echo "done $ec $(date)" > "$celldone"
+  [ -n "$sp" ] && { kill "$sp" 2>/dev/null || true; }
+  echo "[driver] $(date) END   $tag exit=$ec" >> "$PROG"
+  sleep 10
+done
+
+echo "ALL DONE $(date)" > "$MASTERDONE"
+echo "[driver] $(date) SWEEP COMPLETE" >> "$PROG"