perf: 1440p re-measured with the kit - 363 fps, ~12% cost

Closes the 0.1.5 performance task. Same route and preset as 0.1.0 (packaged
Development, Epic scalability, TSR, VSync off, no frame generation, 2560x1440):

  0.1.0                2.42 ms (414 fps)  p99 3.01
  0.1.5 (kit)          2.76 ms (363 fps)  p99 3.64

The 625 kit actors and 8 generated textures cost about 12% of frame time and still
leave roughly six times the 60 fps floor. Frame-time series committed at
Docs/perf/0.1.5-kit-walk-frametimes.csv; comparison table added to
Docs/release-checks.md.

Records the measurement trap once more: runs showing ~105 fps were two overlapping
game instances, not the build - 363 fps reproduced twice on a clean single instance.

MEMORY.md

@@ -474,3 +474,16 @@ Scope: facts and traps that cost time to establish. Planned work lives in [TODO.
   the stale literal cannot come back. Spawn-view score back to **0.72** (best yet).
 - Lesson to keep: **duplicated placement constants drift silently.** The metric that
   caught it was the composition correlation, not a visual review.
+
+## 2026-11-09 — 1440p re-measured with the kit: 363 fps, ~12% cost
+
+- 2560×1440, Epic preset, TSR, VSync off, no frame generation: **2.76 ms average
+  (363 fps)**, p50 2.73, p95 3.17, p99 3.64, max 4.62 — against `0.1.0`'s 2.42 ms
+  (414 fps). The 625 kit actors + 8 generated textures cost about **12 %** and leave
+  ~6× the 60 fps floor.
+- **Variance trap confirmed a third time:** runs reporting ~105 fps (9.5 ms) were
+  two overlapping game instances — an earlier launch had not exited. `pgrep -af
+  Binaries/Linux/GigLine` should show one wrapper + one binary; 363 fps reproduced
+  twice on a clean run. Always count instances before believing a perf number.
+- Series committed at `Docs/perf/0.1.5-kit-walk-frametimes.csv`; comparison table in
+  `Docs/release-checks.md`.