- src/geo drops the ported debug argument checks and the tests that
bitExact already covers; package boundaries accept a directory entry,
so src/geo/ is listed once per group.
- Cesium no longer carries movers and lines nobody draws with: they are
optional engine capabilities. The fake engine and the Cesium camera use
the shared cameraMath; unused contract tables, clock.ticked, the
'finest' surface detail and Navara click statistics are gone.
- ALPR keeps one overlay core and one presentation model for both
engines, bikeshare one station bookkeeping, the Navara ground effects
one definition helper; image atlases, view centres, mover banks and
colours are shared.
- The legacy switch route, the clock offset and rate controls and other
unused exports are removed.
- The acceptance runs the Navara draw, geo import and scope checks;
scenarios use the harness switch and page helpers; the main chunk
check keeps the size budget only and runs once in CI.
Every scenario runs through scripts/qa-strict-harness.mjs: each page, frame and worker gets an ordered block list before it runs (paid hosts and routes first, then only the preview, declared fixtures, keyless probes and cached free tile hosts), switches with real input on the picker, and records its assertions per layer and engine. The runner reads the catalog from the live page, fails any layer without an assertion on either engine, can build and serve a keyless checkout itself, and adds rapid, hidden-tab, context-loss, failure-injection, cold-chunk and soak scenarios. The main chunk gets a 1% size budget.
A picked engine now lives in the switch until it runs; only then is the
address written, so a pick superseded by Back or one that fails rewrites no
entry. An engine-changing history visit holds the outgoing share link, which
neither restores nor writes the visited entry, and the running engine takes
the address back once the switch settles, restoring any entry visited while
it was held or not yet listening. Handed-off layers keep running where the
incoming address agrees with the outgoing one and follow a visited entry
where it differs. A failed recovery keeps the error on the loading screen
with an engine picker for a retry, and a failing reveal of the new globe no
longer blocks the cover removal or later requests.
The engine switch moves out of main.js into src/standalone/engineSwitch.js: every
engine change in the page hands the session off (layers, Director, Contacts,
directions and satellite cameras), whether it came from the picker or from
history. Each attempt has a generation; a failure rolls back to the last engine
that started, requests made during a switch or recovery are reconciled once it
settles, and a picked engine adds its history entry only after it starts. The
first-frame wait only lifts the cover and never fails a started engine; a
hidden tab does not wait. Nothing starts after pagehide, and a failed recovery
leaves the picker usable.
Preserve the camera, map source and layer selection across engine sessions. Restore the previous engine if startup fails and retain local history navigation.
Remember the chosen engine and restore the current view after navigation. Keep the standalone JavaScript UI and retire the Dioxus migration and Cesium removal milestones.