Name the reporting provider in Contacts and Cockpit counts

The Cockpit Contact counts named fixed providers (OpenSky, adsb.lol,
AISStream) while the Layers panel and Contacts named the provider the last
snapshot reported, and the vessels layer kept that name out of getStats(),
so Contacts always said AISStream. Each cohort now carries the provider and
whether it answered as a fallback or from a stale snapshot, and both views
show it the way the Layers row does ("adsb.lol · FALLBACK").

Fixes HAL-721.

docs/CURRENT-STATE.md

@@ -4965,6 +4965,7 @@ silently demoting every later lookup for the session.
 - Enabled Data Layer controls report normalized feed health on the button (`LOADING`, `DEGRADED`, `STALE`, `FALLBACK`, or `UNAVAILABLE`) while the metadata line retains the source and reason. A partial CelesTrak group failure keeps the usable catalog and reports `DEGRADED`; a total outage keeps last-good catalog data visible but reports `UNAVAILABLE`.
 - On activation it focuses the nearest currently observed aircraft across the civilian and military feeds, with military winning an exact distance tie; if none are available, it focuses an observed AIS vessel. The aircraft search is deliberately uncapped and one refresh-tick retry handles initially empty feeds. This is an attention-priority navigation shortcut, not a high-risk, affiliation, or threat classification.
 - A selected aircraft, AIS vessel, or mapped installation gets a 250 km **context window** with nearby cohort counts, nearest examples, source labels, and stale/unavailable reasons. It emits `NEARBY` or `UNKNOWN`; no detection, engagement, affiliation, or sensor-activity conclusion is calculated.
+- Contacts rows and the Cockpit Contact counts name each cohort's provider as its layer row does: the source the last snapshot reported, marked `FALLBACK` or `STALE` in the same cases. A flight snapshot answered by the adsb.lol regional fallback reads `adsb.lol · FALLBACK` everywhere, never `OpenSky`.
 - For a selected live aircraft or vessel, the context window refreshes from the existing tracker/feed position every 750 ms, so nearest distances and cohort counts follow the subject without introducing a duplicate poll loop.
 - Aircraft cohort membership uses every locally loaded, selectable contact inside the 250 km window, including a plane hidden only by horizon culling or because its 3D model owns the visual. Counts and navigation therefore do not change with the current camera angle or billboard/model handoff.
 - Nearby examples in the context panel are focus controls: they use their owning layer's existing selection/tracking path, then frame that contact. Static-installation distances use ellipsoidal surface distance so the count matches the ground-projected context disk.