fix(status): stop false LOAD FAILED from a relayed adsb.lol 429 and the installations zoom prompt

Two independent triggers turned the global status chip red while every layer
was still populated (reproduced at JFK in Cockpit; timeline in the issue).

adsb.lol proxy: a non-OK upstream status was relayed verbatim even with a
12 s-old cache in hand, and the browser layer answers a 429 with a 45 s
cooldown in which every refresh reports "adsb.lol rate limited" without a
network call. The proxy now serves its cached body as STALE on a 429/5xx and
backs off from upstream for Retry-After (bounded), mirroring the OpenSky
proxy. A failure with nothing cached is still relayed.

Mapped installations: the "zoom in" guidance was stored in `error`, so the
manager reported a refresh failure and the chip a LOAD FAILED whenever the
view could not be bounded (Cockpit looks at the horizon). The status is now
set without an error string; the row reads the prompt from `statusMessage`,
and the chip ignores `error` for guidance statuses, matching the carve-out
layerFeedState already has.

src/data/manager.js

@@ -1,4 +1,5 @@
 import { governorRequestRender } from '../renderGovernor.js';
+import { GUIDANCE_STATUSES } from '../loadingFeedback.js';
 import { markDetectionSourcesChanged } from './detection.js';
 function cloneLayerParams(value) {
   if (Array.isArray(value)) return value.map(cloneLayerParams);
@@ -2233,6 +2234,12 @@ export class DataLayerManager {
       }
       return `${stateLabel} · ${source} · ${presentedError}`;
     }
+    // A guidance status carries its prompt in `statusMessage`, not `error`, so
+    // the row still tells the operator what to do without reporting a fault.
+    if (GUIDANCE_STATUSES.includes(String(stats.status || '').toLowerCase())
+        && typeof stats.statusMessage === 'string' && stats.statusMessage.trim()) {
+      return `${source} · ${stats.statusMessage.trim()}`;
+    }
     const ago = stats.lastUpdate ? this._timeAgo(stats.lastUpdate) : 'never';
     if (stats.loading) {
       const loadingLabel = typeof stats.loadingLabel === 'string' && stats.loadingLabel.trim()