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-statefulset.yaml

@@ -0,0 +1,146 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: adopt-a-street-couchdb
+  namespace: adopt-a-street
+  labels:
+    app: couchdb
+spec:
+  clusterIP: None  # Headless service for StatefulSet
+  selector:
+    app: couchdb
+  ports:
+    - port: 5984
+      targetPort: 5984
+      name: couchdb
+    - port: 4369
+      targetPort: 4369
+      name: epmd
+    - port: 9100
+      targetPort: 9100
+      name: couchdb-exporter
+
+---
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: adopt-a-street-couchdb
+  namespace: adopt-a-street
+spec:
+  serviceName: adopt-a-street-couchdb
+  replicas: 1
+  selector:
+    matchLabels:
+      app: couchdb
+  template:
+    metadata:
+      labels:
+        app: couchdb
+    spec:
+      # Place CouchDB on Pi 5 nodes (more RAM)
+      affinity:
+        nodeAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+            nodeSelectorTerms:
+              - matchExpressions:
+                  - key: kubernetes.io/arch
+                    operator: In
+                    values:
+                      - arm64  # Pi 5 architecture
+      containers:
+        - name: couchdb
+          image: couchdb:3.3
+          ports:
+            - containerPort: 5984
+              name: couchdb
+            - containerPort: 4369
+              name: epmd
+            - containerPort: 9100
+              name: couchdb-exporter
+          env:
+            - name: COUCHDB_USER
+              valueFrom:
+                secretKeyRef:
+                  name: adopt-a-street-secrets
+                  key: COUCHDB_USER
+            - name: COUCHDB_PASSWORD
+              valueFrom:
+                secretKeyRef:
+                  name: adopt-a-street-secrets
+                  key: COUCHDB_PASSWORD
+            - name: COUCHDB_SECRET
+              valueFrom:
+                secretKeyRef:
+                  name: adopt-a-street-secrets
+                  key: COUCHDB_SECRET
+            - name: NODENAME
+              value: couchdb@0.adopt-a-street-couchdb.adopt-a-street
+            - name: ERL_FLAGS
+              value: "+K true +A 4"
+          resources:
+            requests:
+              memory: "512Mi"
+              cpu: "250m"
+            limits:
+              memory: "2Gi"
+              cpu: "1000m"
+          volumeMounts:
+            - name: couchdb-data
+              mountPath: /opt/couchdb/data
+            - name: couchdb-config
+              mountPath: /opt/couchdb/etc/local.d
+          livenessProbe:
+            httpGet:
+              path: /_up
+              port: 5984
+            initialDelaySeconds: 30
+            periodSeconds: 10
+            timeoutSeconds: 5
+            failureThreshold: 3
+          readinessProbe:
+            httpGet:
+              path: /_up
+              port: 5984
+            initialDelaySeconds: 5
+            periodSeconds: 10
+            timeoutSeconds: 5
+            failureThreshold: 3
+        - name: couchdb-exporter
+          image: gesellix/couchdb-exporter:latest
+          ports:
+            - containerPort: 9100
+              name: metrics
+          env:
+            - name: COUCHDB_URL
+              value: "http://localhost:5984"
+            - name: COUCHDB_USER
+              valueFrom:
+                secretKeyRef:
+                  name: adopt-a-street-secrets
+                  key: COUCHDB_USER
+            - name: COUCHDB_PASSWORD
+              valueFrom:
+                secretKeyRef:
+                  name: adopt-a-street-secrets
+                  key: COUCHDB_PASSWORD
+          resources:
+            requests:
+              memory: "64Mi"
+              cpu: "50m"
+            limits:
+              memory: "128Mi"
+              cpu: "100m"
+      volumes:
+        - name: couchdb-config
+          configMap:
+            name: couchdb-config
+  volumeClaimTemplates:
+    - metadata:
+        name: couchdb-data
+      spec:
+        accessModes: ["ReadWriteOnce"]
+        resources:
+          requests:
+            storage: 10Gi
+        # Uncomment and set your storage class if needed
+        # storageClassName: local-path