Let a GNSS integrity source set the layer's evidence window

The catalog now passes the gnss-integrity source's windowMs to the layer.
A missing, non-finite or non-positive value keeps the 30-minute default.
The row text now names the window the layer uses instead of a fixed 30 min.

src/layers/gnss/index.js

@@ -70,10 +70,16 @@ export function createGnssIntegrityLayer({
   viewAnchor = defaultGnssViewAnchor,
   now = () => Date.now(),
   monotonicNow = () => performance.now(),
-  windowMs = GNSS_WINDOW_MS,
+  windowMs: requestedWindowMs,
 } = {}) {
   if (typeof source?.getSnapshot !== 'function')
     throw new TypeError('GNSS integrity layer requires a snapshot source');
+  // A source may set its own evidence window; anything but a positive finite
+  // duration keeps the default.
+  const windowMs =
+    Number.isFinite(requestedWindowMs) && requestedWindowMs > 0
+      ? requestedWindowMs
+      : GNSS_WINDOW_MS;
   let _viewer = null;
   let _primitives = null;
   let _request = null;
@@ -375,7 +381,8 @@ export function createGnssIntegrityLayer({
         chips: [],
         info:
           t(
-            'Regional sample · 250 nm radius · cells from visited views over 30 min',
+            'Regional sample · 250 nm radius · cells from visited views over {minutes} min',
+            { minutes: formatNumber(provenance.window.minutes) },
           ) +
           (_lastError && _retryAt
             ? ` · ${translateFeedError(_lastError)} · ${