docs: record rejected duplicate rolling optimization

docs/evidence/duplicate-rolling-lookback-rejection-20260905.json

@@ -0,0 +1,78 @@
+{
+  "schemaVersion": "fidc-duplicate-rolling-lookback-rejection/v1",
+  "measuredAt": "2026-09-05T01:05:00+08:00",
+  "host": "192.168.31.177",
+  "candidateCommits": [
+    "1f02e78b2400c73c5f05351b0beff16d6c724e2a",
+    "e469b0ddf4aa3bb9fe69b785b51ce6c7cf960b90"
+  ],
+  "revertCommit": "5b2a03d416a7bd709680a1adf52013e3eadc199a",
+  "candidate": {
+    "description": "reuse equal lookback values only inside one AdjustedCloseSeries moving_averages_at_end call",
+    "validComponentBenchmark": {
+      "samples": 6,
+      "iterationsPerSample": 3000000,
+      "lookbacks": [1, 2, 3, 1, 2, 3, 1],
+      "repeatedSeconds": 1.40643611,
+      "reusedSeconds": 0.853281932,
+      "speedup": 1.6482666012902287,
+      "checksum": 1458000000.0
+    },
+    "hardwareCounters": {
+      "runId": "btr_1788541184367_2862338_11",
+      "engineSeconds": 8.423,
+      "taskClockMilliseconds": 9030.56,
+      "cycles": 22931608591,
+      "instructions": 28199702874,
+      "branches": 5010114942,
+      "branchMisses": 23586244,
+      "cacheReferences": 268428800,
+      "cacheMisses": 146632717
+    }
+  },
+  "restoredBaseline": {
+    "warmupRunId": "btr_1788541416661_2890172_0",
+    "warmupEngineSeconds": 5.581,
+    "hardwareCounters": {
+      "runId": "btr_1788541455567_2890172_1",
+      "engineSeconds": 6.078,
+      "taskClockMilliseconds": 6643.43,
+      "cycles": 16773013609,
+      "instructions": 28218847364,
+      "branches": 5024236708,
+      "branchMisses": 23209586,
+      "cacheReferences": 266316407,
+      "cacheMisses": 81226408
+    },
+    "runnerBinarySha256": "188269bf0c2ee65d6c11ed37ddddfdaf86695941e8123f69f950054bea39796e"
+  },
+  "comparison": {
+    "candidateInstructionReductionPercent": 0.06784229696471904,
+    "candidateBranchReductionPercent": 0.2810720756590066,
+    "materialSystemImprovementProven": false,
+    "wallTimeComparable": false,
+    "reason": "host-wide thermal and external workload changes produced materially different cache-miss and clock conditions; the instruction reduction itself is below one tenth of one percent"
+  },
+  "businessContract": {
+    "startDate": "2021-08-23",
+    "endDate": "2026-08-28",
+    "frequency": "1d",
+    "matchingType": "next_bar_open",
+    "totalReturn": 0.9219861819172002,
+    "tradeCount": 26088,
+    "canonicalSha256": "b42fea66237d06eadb24f6b8c9e2760e7319fe3699f315b99e01f433ef2aa234",
+    "resultStoreSha256": "92343fb369fea68b2544b654151c5c43a935940580b14afbe8eefb3844f72a54",
+    "allRunsConsistent": true
+  },
+  "remoteArtifacts": [
+    "/srv/fidc/canonical/run/fidc-private/evidence/duplicate-lookback-20260905.json",
+    "/srv/fidc/canonical/run/fidc-private/evidence/duplicate-lookback-low-contention-20260905.json",
+    "/srv/fidc/canonical/run/fidc-private/evidence/duplicate-lookback-perf-stat-candidate-20260905/perf-stat.csv",
+    "/srv/fidc/canonical/run/fidc-private/evidence/duplicate-lookback-perf-stat-baseline-20260905/perf-stat.csv"
+  ],
+  "decision": {
+    "status": "rejected_and_removed",
+    "reason": "the valid microbenchmark improves, but the real five-year workload saves only about 0.068 percent instructions and provides no measurable system-level benefit",
+    "productionEngineCommit": "5b2a03d416a7bd709680a1adf52013e3eadc199a"
+  }
+}