Use afterNavigate for initial loads and URL/history changes. Remove the duplicate onMount fetch. Regression checks require one details request for initial load, next, back and reload, alongside existing retry coverage. Update chart architecture and e2e contract documentation.

Shipping build after lifecycle/coverage fixes versus projection checkpoint: file readiness 429.8 -> 418.3 ms, TBT 129 -> 125 ms; one initial details request instead of two. Shipping default visible/all readiness 477.2/2934.3 ms, TBT 114 ms, heap 18.2 MiB, total gzip JS 191.1 KiB. Original baseline 509.1/3258.9 ms, 130 ms, 18.3 MiB and 228.1 KiB. Three fresh browser samples; no overlapping validation.

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.