test(session): pin the flatter session-store perf baseline

Author: TheGreatAxios

scripts/context-store-perf.test.ts

@@ -5,11 +5,12 @@ import { createOptimizedContextStore } from "../src/session/optimized-context-st
 import { createTempDir } from "../testkit/temporary-dirs.js";
 
 /**
- * Pins the per-turn slope of fs.promises.access, counted the same way
+ * Pins the slope of fs.promises.access, counted the same way
  * scripts/context-store-perf.ts installCounters counts it (every call, and a
  * separate tally when the path is under .git). Synchronous fs is invisible
  * here, same as that script. Two turn counts keep a fixed overhead from hiding
- * a probe that runs once per turn.
+ * a probe that runs once per turn. The commit path no longer pays one access
+ * per turn, so both slopes stay flat.
  */
 const LOW_TURNS = 4;
 const HIGH_TURNS = 12;
@@ -92,7 +93,7 @@ afterEach(() => {
   totals.gitAccess = 0;
 });
 
-test("fs.promises.access grows by a fixed per-turn slope", async () => {
+test("fs.promises.access slope is flat, not per-turn", async () => {
   installCounters();
   await runScenario(LOW_TURNS);
   const low = { access: totals.access, gitAccess: totals.gitAccess };
@@ -101,6 +102,6 @@ test("fs.promises.access grows by a fixed per-turn slope", async () => {
   await runScenario(HIGH_TURNS);
   const high = { access: totals.access, gitAccess: totals.gitAccess };
   const span = HIGH_TURNS - LOW_TURNS;
-  expect((high.access - low.access) / span).toBe(1);
+  expect((high.access - low.access) / span).toBe(0);
   expect((high.gitAccess - low.gitAccess) / span).toBe(0);
 });

scripts/results/session-store-perf-baseline.json

@@ -10,51 +10,51 @@
   ],
   "contextStorePerf": {
     "turnCount": 200,
-    "wallMs": 744,
+    "wallMs": 814,
     "loadedTurns": 250,
-    "totalFsOps": 21396,
-    "gitPathFsOps": 10385,
+    "totalFsOps": 15736,
+    "gitPathFsOps": 7717,
     "fsOps": {
-      "readFile": 10881,
-      "mkdir": 247,
-      "writeFile": 1275,
-      "stat": 3141,
-      "lstat": 4249,
-      "readdir": 1203,
-      "access": 202,
+      "readFile": 7878,
+      "mkdir": 246,
+      "writeFile": 1274,
+      "stat": 2580,
+      "lstat": 2948,
+      "readdir": 611,
+      "access": 1,
       "open": 198
     },
     "gitPathFsOpsByName": {
-      "stat": 1273,
-      "mkdir": 241,
-      "writeFile": 1269,
-      "lstat": 1324,
-      "readFile": 6278
+      "stat": 679,
+      "mkdir": 240,
+      "writeFile": 1268,
+      "lstat": 1067,
+      "readFile": 4463
     },
     "perTurn": {
-      "wallMs": 3.72,
-      "fsOps": 106.98
+      "wallMs": 4.07,
+      "fsOps": 78.68
     }
   },
   "turnPersistenceCensus": {
     "flow": "coalesced",
     "turnCount": 200,
-    "wallMs": 642,
+    "wallMs": 696,
     "loadedTurns": 800,
-    "totalWriteOps": 2088,
-    "gitPathWriteOps": 1678,
+    "totalWriteOps": 2097,
+    "gitPathWriteOps": 1687,
     "byName": {
-      "mkdir": 246,
-      "writeFile": 1642,
+      "mkdir": 251,
+      "writeFile": 1646,
       "appendFile": 200
     },
     "gitByPath": {
-      "mkdir": 240,
-      "writeFile": 1438
+      "mkdir": 245,
+      "writeFile": 1442
     },
     "perTurn": {
-      "wallMs": 3.21,
-      "writeOps": 10.44
+      "wallMs": 3.48,
+      "writeOps": 10.48
     },
     "persistCalls": {
       "writePrompt": 200,