fix(street-level): retire lookups and preserve embedded photos

Clear cancelled lookup loading over an existing photo, release caller abort listeners on internal retirement, surface embedded errors, and permit embedded photos over the clean globe. Add seven regression cases and update runtime documentation. Preserve the published localization and other review fixes.

docs/CURRENT-STATE.md

@@ -4342,7 +4342,8 @@ calls `openNearest`. `provider` is `google` for "Street View", `mapillary`,
 `kartaview` or `panoramax` by name, else the lit source. Stages fail separately (`location`, `view`, `map`,
 `provider`, `layer`, `key`, `imagery`; `view` when cockpit, clean view,
 recording or scene playback hides the panel, checked after the flight and
-before anything switches or loads; an empty `imagery` result names a
+before anything switches or loads; embed mode exempts its own clean-view
+class because the photo is lifted above the globe; an empty `imagery` result names a
 narrowing 360°/flat or SINCE filter the source honours, as `filter`) and a
 newer turn retires the lookup
 (`openNearest`'s `signal` option), so nothing opens after the user moved on.
@@ -4366,9 +4367,13 @@ applies it through the action, and a plain link runs the action once restored
 (one shot: the rewritten hash drops `sl`). In embed mode the rail holding the
 panel is hidden, so an open photo moves to an overlay on the globe
 (`sl-viewer-wrap-embed`) and back when it closes; Esc closes it (in full
-screen, Esc leaves full screen first). A caller's abort is
+screen, Esc leaves full screen first). Image-loading failures render inside
+the embedded overlay, since the panel's error region is hidden with the rail.
+A caller's abort is
 honoured through the viewer's mount and load, not just the lookup, and only
-the lookup that still owns the panel may change its spinner or error. A
+the lookup that still owns the panel may change its spinner or error. Cancelling
+a lookup clears its loading state even when an existing photo stays open;
+internally retired lookups also release the caller's abort listener. A
 passive link's photos stand down if anyone navigated (a gesture, a search,
 the assistant) while the link waited behind its own marks. A plain
 link never loads a photo from a source that bills every load