Add transactional emails (SMTP) and planner features (no-go areas, notes, crash recovery)

Transactional emails:
- Add nodemailer SMTP email module with dev-mode console logging
- Magic link template and welcome template with HTML + plain text
- Wire sendMagicLink into login flow, sendWelcome into registration
- Update privacy page and deploy docs for SMTP configuration

Planner features:
- No-go areas: draw polygons on map (leaflet-geoman), synced via Yjs,
  passed to BRouter as nogos parameter, route recomputes on change
- Session notes: collaborative Y.Text textarea in sidebar tab
- Crash recovery: periodic localStorage save of Yjs state, restore on reconnect
- Rate limit session creation (10/IP/hour) in /new route

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/planner/app/components/NoGoAreaLayer.tsx

@@ -0,0 +1,119 @@
+import { useEffect, useRef, useCallback } from "react";
+import { useMap } from "react-leaflet";
+import L from "leaflet";
+import * as Y from "yjs";
+import "@geoman-io/leaflet-geoman-free";
+import "@geoman-io/leaflet-geoman-free/dist/leaflet-geoman.css";
+
+interface NoGoAreaLayerProps {
+  noGoAreas: Y.Array<Y.Map<unknown>>;
+  doc: Y.Doc;
+  enabled: boolean;
+  onToggle: () => void;
+}
+
+const NO_GO_STYLE: L.PathOptions = {
+  color: "#ef4444",
+  fillColor: "#ef4444",
+  fillOpacity: 0.2,
+  weight: 2,
+};
+
+function yMapToLatLngs(yMap: Y.Map<unknown>): L.LatLng[] {
+  const points = yMap.get("points") as Array<{ lat: number; lon: number }> | undefined;
+  if (!points) return [];
+  return points.map((p) => L.latLng(p.lat, p.lon));
+}
+
+export function NoGoAreaLayer({ noGoAreas, doc, enabled, onToggle }: NoGoAreaLayerProps) {
+  const map = useMap();
+  const layerGroupRef = useRef<L.LayerGroup>(L.layerGroup());
+  const polygonMapRef = useRef<Map<number, L.Polygon>>(new Map());
+  const suppressObserverRef = useRef(false);
+
+  // Sync Yjs → Leaflet layers
+  const syncLayers = useCallback(() => {
+    const lg = layerGroupRef.current;
+    // Clear all existing polygons
+    lg.clearLayers();
+    polygonMapRef.current.clear();
+
+    for (let i = 0; i < noGoAreas.length; i++) {
+      const yMap = noGoAreas.get(i);
+      const latLngs = yMapToLatLngs(yMap);
+      if (latLngs.length < 3) continue;
+
+      const polygon = L.polygon(latLngs, NO_GO_STYLE);
+      polygon.on("contextmenu", (e) => {
+        L.DomEvent.preventDefault(e as unknown as Event);
+        suppressObserverRef.current = true;
+        noGoAreas.delete(i, 1);
+        suppressObserverRef.current = false;
+        syncLayers();
+      });
+      lg.addLayer(polygon);
+      polygonMapRef.current.set(i, polygon);
+    }
+  }, [noGoAreas]);
+
+  // Add/remove layer group from map
+  useEffect(() => {
+    const lg = layerGroupRef.current;
+    lg.addTo(map);
+    return () => {
+      lg.removeFrom(map);
+    };
+  }, [map]);
+
+  // Observe Yjs changes
+  useEffect(() => {
+    const observer = () => {
+      if (!suppressObserverRef.current) {
+        syncLayers();
+      }
+    };
+    noGoAreas.observeDeep(observer);
+    syncLayers();
+    return () => noGoAreas.unobserveDeep(observer);
+  }, [noGoAreas, syncLayers]);
+
+  // Geoman drawing controls
+  useEffect(() => {
+    if (enabled) {
+      map.pm.enableDraw("Polygon", {
+        pathOptions: NO_GO_STYLE,
+        snappable: false,
+      });
+    } else {
+      map.pm.disableDraw();
+    }
+
+    const handleCreate = (e: { layer: L.Layer }) => {
+      const layer = e.layer as L.Polygon;
+      const latLngs = (layer.getLatLngs()[0] as L.LatLng[]);
+      const points = latLngs.map((ll) => ({ lat: ll.lat, lon: ll.lng }));
+
+      // Remove the geoman-created layer (we'll render from Yjs)
+      map.removeLayer(layer);
+
+      // Add to Yjs
+      const yMap = new Y.Map();
+      yMap.set("points", points);
+      doc.transact(() => {
+        noGoAreas.push([yMap]);
+      });
+
+      // Exit draw mode
+      onToggle();
+    };
+
+    map.on("pm:create", handleCreate);
+
+    return () => {
+      map.pm.disableDraw();
+      map.off("pm:create", handleCreate);
+    };
+  }, [map, enabled, noGoAreas, doc, onToggle]);
+
+  return null;
+}