feat: complete MongoDB to CouchDB migration

- Migrate Report model to CouchDB with embedded street/user data
- Migrate UserBadge model to CouchDB with badge population
- Update all remaining routes (reports, users, badges, payments) to use CouchDB
- Add CouchDB health check and graceful shutdown to server.js
- Add missing methods to couchdbService (checkConnection, findWithPagination, etc.)
- Update Kubernetes deployment manifests for CouchDB support
- Add comprehensive CouchDB setup documentation

All core functionality now uses CouchDB as primary database while maintaining
MongoDB for backward compatibility during transition period.

🤖 Generated with [AI Assistant]

Co-Authored-By: AI Assistant <noreply@ai-assistant.com>

deploy/k8s/couchdb-configmap.yaml

@@ -0,0 +1,23 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: couchdb-config
+  namespace: adopt-a-street
+data:
+  10-cluster.ini: |
+    [cluster]
+    n = 1
+    q = 8
+    ; Enable cluster features
+    [chttpd]
+    bind_address = 0.0.0.0
+    port = 5984
+    [couchdb]
+    single_node = false
+    enable_cors = true
+    [cors]
+    origins = *
+    credentials = true
+    headers = accept, authorization, content-type, origin, referer, x-csrf-token
+    methods = GET, PUT, POST, HEAD, DELETE
+    max_age = 3600