Use no-op fts-client if disabled + push this flag to the webui

modules/restserver/src/main/scala/docspell/restserver/RestAppImpl.scala

@@ -39,5 +39,6 @@ object RestAppImpl {
   private def createFtsClient[F[_]: ConcurrentEffect: ContextShift](
       cfg: Config
   )(client: Client[F]): Resource[F, FtsClient[F]] =
-    SolrFtsClient(cfg.fullTextSearch.solr, client)
+    if (cfg.fullTextSearch.enabled) SolrFtsClient(cfg.fullTextSearch.solr, client)
+    else Resource.pure[F, FtsClient[F]](FtsClient.none[F])
 }

modules/restserver/src/main/scala/docspell/restserver/webapp/Flags.scala

@@ -13,7 +13,8 @@ case class Flags(
     baseUrl: LenientUri,
     signupMode: SignupConfig.Mode,
     docspellAssetPath: String,
-    integrationEnabled: Boolean
+    integrationEnabled: Boolean,
+    fullTextSearchEnabled: Boolean
 )
 
 object Flags {
@@ -23,7 +24,8 @@ object Flags {
       cfg.baseUrl,
       cfg.backend.signup.mode,
       s"/app/assets/docspell-webapp/${BuildInfo.version}",
-      cfg.integrationEndpoint.enabled
+      cfg.integrationEndpoint.enabled,
+      cfg.fullTextSearch.enabled
     )
 
   implicit val jsonEncoder: Encoder[Flags] =