Offline-Fallbacks für diary, poison, map + SW-Erweiterung

- sw.js: /api/places, /api/breeder/map-markers, /api/gassi-zeiten in _CACHEABLE_GET; /api/lost/report und /api/walks in _QUEUEABLE
- diary.js: localStorage-Cache pro Hund, Fallback bei Offline mit Toast
- poison.js: localStorage-Cache, Fallback bei Offline mit Toast (sicherheitsrelevant)
- map.js: POI-Cache (places/poison/breeders) in localStorage, Offline-Toast + Fallback auf gecachte Daten

backend/static/sw.js

@@ -119,6 +119,8 @@ const _QUEUEABLE = [
   { re: /^\/api\/training\/sessions$/,             methods: ['POST'] },
   { re: /^\/api\/training\/progress$/,             methods: ['POST'] },
   { re: /^\/api\/poison$/,                         methods: ['POST'] },
+  { re: /^\/api\/lost\/report$/,                   methods: ['POST'] },
+  { re: /^\/api\/walks$/,                          methods: ['POST'] },
 ];
 function _isQueueable(pathname, method) {
   return _QUEUEABLE.some(q => q.methods.includes(method) && q.re.test(pathname));
@@ -139,6 +141,9 @@ const _CACHEABLE_GET = [
   /^\/api\/wiki\/rassen/,
   /^\/api\/dogs\/\d+\/diary\/stats/,
   /^\/api\/routes$/,
+  /^\/api\/places$/,
+  /^\/api\/breeder\/map-markers$/,
+  /^\/api\/gassi-zeiten/,
   // Drei Welten — offline-fähig
   /^\/api\/streak\/\d+/,
   /^\/api\/forum\/threads/,