Add ADS-B, AIS, and ALPR map layers with live CoT streaming.

Ingest aircraft and vessel tracks via OSINT feeds and tactical CoT, expose viewport-filtered SSE to the map, and add an OSM ALPR layer with tiled caching and performant marker sync.

server/utils/cotSnapshot.js

@@ -0,0 +1,15 @@
+import {
+  COT_OSINT_TTL_MS,
+  COT_SSE_MAX_ENTITIES,
+  COT_TAK_FILTER_BBOX,
+  COT_TTL_MS,
+} from './constants.js'
+
+export function getCotSnapshotOpts() {
+  return {
+    ttlMs: COT_TTL_MS,
+    osintTtlMs: COT_OSINT_TTL_MS,
+    takFilterBbox: COT_TAK_FILTER_BBOX,
+    maxEntities: COT_SSE_MAX_ENTITIES,
+  }
+}