Add per-waypoint notes and nearby POI snap to Planner

- `note` field on Waypoint type, stored in Yjs Y.Map and exported as
  `<desc>` inside `<wpt>` in GPX
- Inline textarea note editing in WaypointSidebar with auto-resize,
  character counter (500 max), save-on-blur, Escape cancel
- Note indicator dot on map markers; note tooltip on hover
- `useNearbyPois` hook: fetches POIs within 500m of selected waypoint
  via Overpass proxy, 500ms debounce, AbortController, 60s rate-limit
  suppression
- NearbyPoiMarkers component: renders POI markers on map for selected
  waypoint with snap-to-POI on click
- Nearby section in WaypointSidebar: list with snap buttons, spinner,
  empty/rate-limited states, "Show more" toggle (5 → all)
- Unit tests for fetchNearbyPois bbox geometry and snap-to-POI Yjs
  transaction behaviour

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/i18n/src/locales/de.ts

@@ -88,6 +88,18 @@ export default {
       viewpoints: "Aussichtspunkte",
       toilets: "Toiletten",
     },
+    waypoint: {
+      notePlaceholder: "Notiz hinzufügen…",
+      noteCounter: "{{count}} / {{max}}",
+    },
+    nearbyPoi: {
+      heading: "In der Nähe",
+      loading: "Suche nach nahegelegenen Orten…",
+      empty: "Keine nahegelegenen Orte gefunden",
+      rateLimited: "POI-Abfrage vorübergehend nicht verfügbar",
+      snap: "Hier einrasten",
+      showMore: "Mehr anzeigen",
+    },
     noGoAreas: {
       draw: "Sperrgebiet zeichnen",
       cancel: "Sperrgebiet abbrechen",

packages/i18n/src/locales/en.ts

@@ -88,6 +88,18 @@ export default {
       viewpoints: "Viewpoints",
       toilets: "Toilets",
     },
+    waypoint: {
+      notePlaceholder: "Add a note...",
+      noteCounter: "{{count}} / {{max}}",
+    },
+    nearbyPoi: {
+      heading: "Nearby",
+      loading: "Looking up nearby points of interest…",
+      empty: "No nearby points of interest found",
+      rateLimited: "POI lookup unavailable",
+      snap: "Snap here",
+      showMore: "Show more",
+    },
     noGoAreas: {
       draw: "Draw no-go area",
       cancel: "Cancel no-go area",