Audit package refresh: Window 1 supported claims + risk register

Refresh the standing audit package now that B1' / B2 / B3 are complete.

current_results/characterization_claim_matrix.md
  Flips seven entries from "not_yet_supported" / "partially_supported"
  to "supported" with pointers into window_1_results/. New entries
  cover per-session sequentiality, KV per request, real reuse
  decomposition, theoretical APC ceiling, the LMetric locality gap,
  Unified breaking the locality-vs-latency tradeoff, B2 causal
  interference proof, sticky's interference inflation, and the
  partial heavy-tail / hot-spot story. B4 SRR + B5 attribution stay
  "not_yet_supported" (Window 2 work).

current_results/main_claim_allowed_runs.md
  New "Allowed For Routing-Policy Comparison" section pins the five
  B3 policy directories. New "Allowed For PD-colo Interference"
  section pins the B2 sweep. Legacy section retained for the
  pre-instrumentation 200/500/1000-req runs.

current_results/reviewer_risk_register.md
  Marks the two old "high"-severity risks (sequentiality / reuse
  decomposition) as resolved; adds new entries for the APC
  contamination empirics, the b3_analyze.sh truncate-write bug that
  cost unified's interference index, the GPU-0 EngineCore ghost
  cleanup, the saturated-replay caveat for trace-timestamp dispatch,
  and the synthetic B2 decode workload.

current_results/all_figures_index.md
  Adds the 8 new Window 1 figures alongside the existing 6 from the
  legacy summarize_runs run.

current_results/reproduction_commands.sh
  Records the full B3 + B2 + figure pipeline.

analysis/characterization_todo_for_interns.md
  Updates the Progress Snapshot table: B0, B1, B2, B3, B6 all DONE;
  only B4 and B5 remain (Window 2).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

analysis/characterization/current_results/characterization_claim_matrix.md

@@ -1,11 +1,19 @@
 # Characterization Claim Matrix
 
+Updated 2026-05-25 after Window 1 (B1' KV-footprint + reuse, B3 5-policy
+sweep, B2 PD-colo interference microbench).
+
 | Claim | Status | Supporting Data | Needed Next | Reviewer Risk |
 |---|---|---|---|---|
-| Batch 0 substrate audit is only partially complete for existing runs. | `partially_supported` | metrics.jsonl lacks actual dispatch/finish timestamps in current artifacts. | Add request dispatch and finish/error timestamps to future replayer/proxy metrics. | Cannot use these runs to prove online per-session sequentiality. |
-| Batch 1 workload shape can be characterized from formatted traces and metrics. | `supported_for_trace_shape` | Full compact trace CPU summary in `full_trace_summary.json`: input p50/p90/p99 = 20k/87.9k/125.5k, output p50/p90/p99 = 80/811/6.6k, top 1% sessions hold 46.5% of input-token mass. | Add cache-hit joined records for actual reuse decomposition. | Actual cache reuse decomposition needs cached_tokens joined with hash_ids. |
-| Static PD separation is worse than combined in existing 200-request GPU A/B. | `supported_by_existing_artifact` | outputs/gpu_ab_combined vs outputs/gpu_ab_pdsep metrics.summary.json. | Refresh with PD matrix, multiple seeds, cudagraph-enabled methodology. | Legacy run has no per-stage TTFT breakdown and no step-level KV occupancy. |
-| Elastic transfer-based migration does not improve high-contention 500-request run. | `supported_by_existing_artifact` | outputs/contention_16s_ts10 vs outputs/contention_16s_elastic metrics.summary.json and gpu_util.csv. | Attribute whether failure is trigger quality, transfer overhead, or wrong load regime. | Existing metrics lack actual sequentiality proof and per-request transfer waterfall. |
-| PD-colo prefill/decode interference is not yet directly proven by step-level data in this package. | `not_yet_supported` | No decode-step and prefill-overlap timestamp artifact found in summarized runs. | Run Batch 2 controlled same-worker/different-worker injection with step timestamps. | Cannot claim interference as causal without Batch 2. |
-| Session hot-spot residual imbalance is suggested but not fully attributed. | `partially_supported` | gpu_util.csv shows per-GPU mean-util imbalance in existing runs. | Collect per-worker queue delay, session-to-worker map, and per-session token mass per worker. | GPU util imbalance alone is not enough to prove session hot-spot. |
-| SRR is not measured by existing fixed-request runs. | `not_yet_supported` | No arrival-rate sweep artifacts found. | Implement Batch 4 Poisson session-arrival SRR sweep. | Latency-at-one-load cannot support sustainable throughput claim. |
+| Per-session sequentiality is enforced when replayer + proxy carry the new join fields. | `supported` | A1 unix timestamps (t_dispatch/t_first_token/t_finish_unix) and X-Request-Id passthrough; smoke validation 2026-05-25 confirmed 30/30 join coverage. | Use this stack for all Window 2 B4/B5 SRR runs. | Legacy outputs/ without these fields still cannot be re-classified as `online_realistic`. |
+| Agentic workload is long-input / short-output / heavy-tail session mass. | `supported` | Full trace CPU summary (full_trace_summary.json): input p50/p90/p99 = 20k/87.9k/125.5k; top 1% sessions hold 46.5% of input mass. Full trace 2.11M requests, 1.31M sessions. | — | Sample trace (w600) percentiles inherit from this full trace but should not be extrapolated. |
+| KV per request for Qwen3-Coder-30B-A3B is 98304 B/token; p50/p90/p99 footprint = 1.83/8.04/11.49 GiB. | `supported` | window_1_results/kv_footprint_summary.json; computed from model config and full trace input lengths. | — | Assumes bf16; would scale for fp8/int8 quant. |
+| Workload reuse is overwhelmingly intra-session. | `supported` | Real reuse decomposition from w600 lmetric run: intra 93.2%, cross 5.7%, shared 1.1% (window_1_results/lmetric_reuse.json). Theoretical any-vs-intra ceiling gap 0.7 pp. | — | Trace-specific; ChatGPT-style workloads with long system prompts would shift toward shared-prefix. |
+| Theoretical APC ceiling on w600 trace is 79.6% (intra) / 80.3% (any-session). | `supported` | window_1_results/apc_upper_w600.json from block-level trie walk on `hash_ids`. | — | Assumes infinite per-worker cache (no eviction); achieved values must be read as fraction of this ceiling. |
+| Cache-aware LMetric leaves a measurable locality gap (22.7 pp). | `supported` | lmetric achieved 56.9% vs intra-session ceiling 79.6%; B3 sweep window_1_results/b3_policy_comparison.json. | — | sticky data shows the gap can be recovered by harder affinity. |
+| Hybrid affinity (`unified`) breaks the locality-vs-latency tradeoff. | `supported` | unified APC 79.4% (97% of intra ceiling) AND TTFT p90 7.24 s (lmetric is 15.6 s). | — | unified concentrates a single very hot worker (engine_4 at 37.7 s p90); hotspot_index 3.35. |
+| Same-worker prefill-decode interference is causal, not correlation. | `supported` | B2 microbench: different-worker control idx 0.92-1.02 across 32× prefill-size variation; same-worker TTFT idx scales 2.15× (2k) → 218× (65k). window_1_results/b2_sweep_summary.json. | — | Synthetic decode load (256-token prompts at 4 req/s) bounds the realism; production behavior is layered on top of B3. |
+| Hard session affinity (`sticky`) inflates same-worker prefill-decode interference. | `supported` | sticky interference_index 13.65 vs lmetric 6.53; sticky's slow-request breakdown 57% same-worker overlap vs lmetric 23%. | — | Confirms the B2 causal claim observed at the system level. |
+| Heavy-tail sessions are a contributor to hot-spot but not the sole cause. | `supported` | Cap-8 trace (37% requests dropped) reduces hotspot_index only 13% (2.24 → 1.94). | Run capped under unified to see whether unified's hotspot also persists. | Reviewer might counter that cap=8 is too soft; a stricter cap could be tried. |
+| SRR per policy under SLO is not yet measured. | `not_yet_supported` | B3 was driven by trace timestamps with strict session sequentiality; saturation is reached but not parameterized. | Run B4 with the A4 open-loop Poisson loadgen, per-class SLO, 5 policies × λ binary search. | Without B4 the paper cannot claim "policy X sustains higher load than Y". |
+| Failure attribution near SRR boundary is not yet measured. | `not_yet_supported` | B5 protocol exists; no runs. | After B4, rerun each policy at 0.9× / 1.0× / 1.1× of its SRR_max with the same instrumentation, label slow requests. | The current `joined_analysis.label_slow_requests` is the labeler; needs SRR boundaries to point at. |