Feature: Gassi-Treffen — Orts-Autocomplete, Modal-UX, Teilnehmerliste, Karten-Fix

- Orts-/POI-Suche mit GPS und Vorschlägen (wie Tagebuch) + Mini-Karte im Formular
- Stornieren/Austreten als Zwei-Klick-Pattern (kein UI.modal.confirm in Modals)
- Teilnehmerliste im Detail-Modal mit User-Namen und Hunden
- Leaflet invalidateSize auf 150ms (Memory-Regel), _loadLeaflet robuster
- /api/walks/nearby Backend-Endpunkt (vor /{walk_id} Route)
- SW by-v203, APP_VER 169

backend/routes/walks.py

@@ -1,6 +1,7 @@
 """BAN YARO — Gassi-Treffen"""
 
 import math
+import httpx
 from datetime import date
 from fastapi import APIRouter, Depends, HTTPException
 from pydantic import BaseModel
@@ -20,6 +21,10 @@ def _haversine(lat1, lon1, lat2, lon2):
     return 2 * R * math.asin(math.sqrt(a))
 
 
+def _haversine_km(lat1, lon1, lat2, lon2):
+    return _haversine(lat1, lon1, lat2, lon2) / 1000
+
+
 # ------------------------------------------------------------------
 # Schemas
 # ------------------------------------------------------------------
@@ -103,6 +108,79 @@ async def create_walk(data: WalkCreate, user=Depends(get_current_user)):
     return {**dict(row), 'teilnehmer_count': 0}
 
 
+# ------------------------------------------------------------------
+# GET /api/walks/nearby — POI-Suche für Treffpunkt-Autocomplete
+# WICHTIG: Muss VOR /{walk_id} stehen (FastAPI Route-Reihenfolge)
+# ------------------------------------------------------------------
+@router.get("/nearby")
+async def nearby_places(lat: float, lon: float, user=Depends(get_current_user)):
+    results = []
+
+    with db() as conn:
+        # 1. User-eigene Places
+        places = conn.execute(
+            "SELECT name, typ, lat, lon FROM places WHERE lat IS NOT NULL",
+        ).fetchall()
+        for p in places:
+            km = _haversine_km(lat, lon, p["lat"], p["lon"])
+            if km <= 5:
+                results.append({"name": p["name"], "type": p["typ"] or "place",
+                                 "lat": p["lat"], "lon": p["lon"],
+                                 "distance_m": int(km * 1000), "source": "places"})
+
+        # 2. Gecachte OSM-POIs
+        osm = conn.execute(
+            "SELECT name, type, lat, lon FROM osm_pois WHERE name IS NOT NULL AND name != ''"
+        ).fetchall()
+        for p in osm:
+            km = _haversine_km(lat, lon, p["lat"], p["lon"])
+            if km <= 2:
+                results.append({"name": p["name"], "type": p["type"],
+                                 "lat": p["lat"], "lon": p["lon"],
+                                 "distance_m": int(km * 1000), "source": "osm"})
+
+    # 3. Overpass: benannte POIs in 1000m
+    try:
+        async with httpx.AsyncClient(timeout=6) as client:
+            q = (
+                f'[out:json][timeout:6];'
+                f'(node["name"]["leisure"](around:1000,{lat},{lon});'
+                f' node["name"]["amenity"](around:1000,{lat},{lon});'
+                f' node["name"]["tourism"](around:1000,{lat},{lon});'
+                f' way["name"]["leisure"](around:1000,{lat},{lon});'
+                f');out center;'
+            )
+            r = await client.post("https://overpass-api.de/api/interpreter",
+                                  data={"data": q})
+            if r.status_code == 200:
+                for el in r.json().get("elements", []):
+                    name = el.get("tags", {}).get("name")
+                    if not name:
+                        continue
+                    elat = el.get("lat") or el.get("center", {}).get("lat")
+                    elon = el.get("lon") or el.get("center", {}).get("lon")
+                    if elat is None or elon is None:
+                        continue
+                    km = _haversine_km(lat, lon, elat, elon)
+                    if km <= 1:
+                        results.append({"name": name, "type": "osm",
+                                         "lat": elat, "lon": elon,
+                                         "distance_m": int(km * 1000), "source": "osm"})
+    except Exception:
+        pass
+
+    # Deduplizieren nach Name + Sortieren nach Distanz
+    seen = set()
+    unique = []
+    for r in sorted(results, key=lambda x: x["distance_m"]):
+        key = r["name"].lower()
+        if key not in seen:
+            seen.add(key)
+            unique.append(r)
+
+    return unique[:20]
+
+
 # ------------------------------------------------------------------
 # GET /api/walks/{id} — Detail mit Teilnehmerliste
 # ------------------------------------------------------------------