Generate the active focus guide instead of retaining a hidden SVG circle for every observation. Preserve primary point radius, fill and stroke. Hover does not reconstruct the scene.

Exploratory checkpoint after mount: dashboard heap 22.9 -> 21.1 MiB and initial observed TBT 153 -> 107 ms. This checkpoint preceded the corrected primary-focus resolver, so it is diagnostic rather than final interaction evidence. The corrected guide passed full e2e and final real-stage QA. Final series count/value/hover contracts are unchanged.

Checkpoint measurements above predate the final QA lifecycle/coverage fixes and are not isolated shipping effects. Combined shipping benchmark: 477.2/2934.3 ms default visible/all charts, 114 ms observed initial TBT, 18.2 MiB retained heap and 191.1 KiB gzip JS. Original baseline: 509.1/3258.9 ms, 130 ms, 18.3 MiB, 228.1 KiB. Layer 3: 569.3/4271.3 ms, 159 ms, 29.9 MiB, 202.4 KiB. Baseline dates, five API runs, three fresh contexts per page and one warmup; no concurrent QA/build/dev work. Shipping artifacts: /tmp/atlantis-frontend-overhaul/perf/layer4-shipping/results.json. Full gates pass with 220 web and 70 e2e tests.