Add ADS-B, AIS, and ALPR map layers with live CoT streaming (#36)

## Summary

- **ADS-B & AIS:** OpenSky and AISStream OSINT feeds upsert into the CoT store; tactical tracks still arrive via adsbcot/aiscot on `:8089`. Map clients subscribe via `GET /api/cot/stream` (SSE) with viewport bbox filtering and Air / Surface / Team layer toggles.
- **ALPR (Flock/OSM):** Toggleable license-plate reader layer sourced from OpenStreetMap, with SQLite cache, Overpass fallback, tiled viewport fetching, and clustered markers with direction cones.
- **Map performance:** Ring-based tile selection (fixes zoom-out crash), immutable tile cache, incremental marker sync, split cluster load/query, and padded SSE bbox to reduce reconnect churn.

## Docs

- `docs/tracking.md` — ADS-B/AIS accuracy tiers, freshness, self-hosted receivers, optional OSINT API keys
- `docs/map-and-cameras.md` — ALPR layer and map behavior updates

---------

Co-authored-by: Madison Grubb <madison@elastiflow.com>
Reviewed-on: #36

app/assets/css/main.css

@@ -16,6 +16,9 @@
   .kestrel-btn-secondary { @apply rounded border border-kestrel-border px-4 py-2 text-sm text-kestrel-text transition-colors hover:bg-kestrel-border; }
   .kestrel-context-menu-item { @apply block w-full px-3 py-1.5 text-left text-sm text-kestrel-text transition-colors hover:bg-kestrel-border; }
   .kestrel-context-menu-item-danger { @apply block w-full px-3 py-1.5 text-left text-sm text-red-400 transition-colors hover:bg-kestrel-border; }
+  .kestrel-cot-layer-btn { @apply rounded px-1.5 py-0.5 text-kestrel-muted transition-colors hover:text-kestrel-text; }
+  .kestrel-cot-layer-btn-active { @apply bg-kestrel-border text-kestrel-accent; }
+  .cot-icon-rotatable { @apply inline-flex origin-center; }
   .kestrel-panel-base { @apply flex flex-col border border-kestrel-border bg-kestrel-surface; }
   .kestrel-panel-inline { @apply rounded-lg shadow-glow; }
   .kestrel-panel-overlay { @apply absolute right-0 top-0 z-[1000] h-full w-full border-l shadow-glow md:w-[420px] shadow-glow-panel; }
@@ -84,12 +87,14 @@
 }
 .kestrel-map-container .leaflet-control-zoom,
 .kestrel-map-container .leaflet-control-locate,
+.kestrel-map-container .leaflet-control-alpr,
 .kestrel-map-container .savetiles.leaflet-bar {
   @apply rounded-md overflow-hidden font-mono border border-kestrel-glow shadow-glow-sm;
   border-color: rgba(34, 201, 201, 0.35) !important;
 }
 .kestrel-map-container .leaflet-control-zoom a,
 .kestrel-map-container .leaflet-control-locate,
+.kestrel-map-container .leaflet-control-alpr,
 .kestrel-map-container .savetiles.leaflet-bar a {
   @apply w-8 h-8 leading-8 bg-kestrel-surface text-kestrel-text border-none rounded-none text-lg font-semibold no-underline transition-all duration-150;
   width: 32px !important;
@@ -105,9 +110,14 @@
 }
 .kestrel-map-container .leaflet-control-zoom a:hover,
 .kestrel-map-container .leaflet-control-locate:hover,
+.kestrel-map-container .leaflet-control-alpr:hover,
 .kestrel-map-container .savetiles.leaflet-bar a:hover {
   @apply bg-kestrel-surface-hover text-kestrel-accent shadow-glow-md text-shadow-glow-md;
 }
+.kestrel-map-container .leaflet-control-alpr[aria-pressed="true"] {
+  color: #ef4444 !important;
+  box-shadow: 0 0 8px rgba(239, 68, 68, 0.45);
+}
 .kestrel-map-container .savetiles.leaflet-bar {
   @apply flex flex-col;
 }
@@ -119,12 +129,38 @@
   padding: 6px 10px !important;
   font-size: 11px !important;
 }
-.kestrel-map-container .leaflet-control-locate {
+.kestrel-map-container .leaflet-control-locate,
+.kestrel-map-container .leaflet-control-alpr {
   @apply flex items-center justify-center p-0 cursor-pointer;
 }
-.kestrel-map-container .leaflet-control-locate svg {
+.kestrel-map-container .leaflet-control-locate svg,
+.kestrel-map-container .leaflet-control-alpr svg {
   color: currentColor;
 }
+.kestrel-map-container .alpr-cone {
+  display: inline-flex;
+  transform-origin: center center;
+}
+.kestrel-map-container .alpr-cluster-icon {
+  background: transparent;
+  border: none;
+}
+.kestrel-map-container .alpr-cluster {
+  @apply flex items-center justify-center rounded-full bg-red-500/90 font-mono text-xs font-semibold text-white;
+  width: 100%;
+  height: 100%;
+  box-shadow: 0 0 8px rgba(239, 68, 68, 0.5);
+}
+.kestrel-map-container .cot-cluster-icon {
+  background: transparent;
+  border: none;
+}
+.kestrel-map-container .cot-cluster {
+  @apply flex items-center justify-center rounded-full bg-sky-500/90 font-mono text-xs font-semibold text-white;
+  width: 100%;
+  height: 100%;
+  box-shadow: 0 0 8px rgba(56, 189, 248, 0.5);
+}
 .kestrel-map-container .live-session-icon {
   animation: live-pulse 1.5s ease-in-out infinite;
 }