feat(server): implement doc service (#9961)

close CLOUD-94

.github/helm/affine/charts/graphql/templates/deployment.yaml

@@ -118,6 +118,8 @@ spec:
                 key: stripeWebhookKey
           - name: DOC_MERGE_INTERVAL
             value: "{{ .Values.app.doc.mergeInterval }}"
+          - name: DOC_SERVICE_ENDPOINT
+            value: "{{ .Values.global.docService.endpoint }}"
           {{ if .Values.app.experimental.enableJwstCodec }}
           - name: DOC_MERGE_USE_JWST_CODEC
             value: "true"