fix(firms): drop LIVE from the row's source and the voice answer for a snapshot that ends at a set time

The catalog source 'NASA FIRMS · LIVE' still led the row; getStats() now
names the source 'NASA FIRMS' for such a snapshot. get_active_fires says
"in the 24 hours to" its end and reports window_end. The end is checked
to be a printable time, cleared under KEY REQUIRED, the test moves next
to the layer, and the changelog and CURRENT-STATE describe it.

server/providers/firms.js

@@ -145,15 +145,16 @@ export async function fetchFirms(
  *
  * Routes:
  *   GET /api/firms        → {fetchedAt, stale, ttlMs, sources, count, fires}
- *
- * The trailing 24 hours to now. A source may instead answer the 24 hours to
- * a set time, naming its end as `at` (epoch ms); the layer's row then shows
- * that time rather than LIVE. This proxy never sets `at`.
  *   GET /api/firms/status → {hasKey, lastFetch, count, stale, ttlMs, transactions}
  *
  * Keyless (no FIRMS_MAP_KEY): /api/firms → 503 {error:'no_key'}; status →
  * {hasKey:false}. Upstream is never touched without a key.
  *
+ * /api/firms answers the trailing 24 hours to now. A source may instead
+ * answer the 24 hours to a set time, naming its end as `at` (epoch ms); the
+ * layer's row then shows that time rather than LIVE. This proxy never sets
+ * `at`.
+ *
  * @returns {import('vite').Plugin}
  */
 export function firmsProxy() {