feat(osm): user-facing UX — POI sidebar + search filter + docs

* Listing detail: drop the new <NearbyPoiSidebar> below the price card
  with default 1.5km radius and 6 categories (school/secondary/hospital/
  market/bank/metro). Reads property.lat/lng — no-op when unset.
* KCN detail: same component but 3km radius with the categories that
  matter for industrial parks (hospital/bank/gas/bus/metro/police).
* New <PoiSearchFilter> widget for the search page: pill button →
  popover with radius dropdown (300m..5km), 3 quick presets ("Family",
  "Commute", "Convenience"), and 6 grouped category checkboxes. Wires
  to a `PoiNearbyConstraint` value so callers can pass it into search
  filters when they're ready.
* docs/osm-data-model.md: canonical reference for every OSM-sourced
  table, sync cadence, quality gates, runbook for ops, and a clear
  "how to add a new POI category" guide.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/components/listings/listing-detail-client.tsx

@@ -6,6 +6,7 @@ import * as React from 'react';
 import { AddToCompareButton } from '@/components/comparison/add-to-compare-button';
 import { AiAdviceCards } from '@/components/listings/ai-advice-cards';
 import { ImageGallery } from '@/components/listings/image-gallery';
+import { NearbyPoiSidebar } from '@/components/poi/nearby-poi-sidebar';
 import { InquiryModal } from '@/components/listings/inquiry-modal';
 import { PriceHistoryChart } from '@/components/listings/price-history-chart';
 import { ReportListingModal } from '@/components/listings/report-listing-modal';
@@ -897,6 +898,15 @@ export function ListingDetailClient({ listing }: ListingDetailClientProps) {
             onOpenChange={setReportOpen}
           />
 
+          {/* OSM POI nearby — schools, hospitals, markets, banks, metro… */}
+          {property.latitude != null && property.longitude != null && (
+            <NearbyPoiSidebar
+              lat={property.latitude}
+              lng={property.longitude}
+              radius={1500}
+            />
+          )}
+
           {/* Stats */}
           <Card>
             <CardContent className="pt-5">