Fix Portal, Remote Favorites and Renaming

backend/include/backend/opener.hpp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <shared_data/opener_capabilities.hpp>
+
 #include <expected>
 #include <filesystem>
 #include <memory>
@@ -24,6 +26,13 @@ class Opener
      */
     std::expected<void, std::string> openInFileManager(std::filesystem::path const& path);
 
+    /**
+     *  @brief Probe the platform's external-open facilities and report which calls are expected
+     *         to succeed. Called once at startup by the frontend via RPC so it can gray out
+     *         "Open" / "Open With" / "Open in File Manager" menu entries and warn the user.
+     */
+    SharedData::OpenerCapabilities capabilities() const;
+
   private:
     struct Implementation;
     std::unique_ptr<Implementation> impl_;

backend/include/backend/rpc_filesystem.hpp

@@ -29,6 +29,7 @@ class RpcFilesystem : public RpcHelper::StrandRpc
     void registerWriteFile();
     void registerOpen();
     void registerOpenInFileManager();
+    void registerOpenerCapabilities();
 
   private:
     Persistence::LocalFilesystemOptions options_;

backend/source/backend/CMakeLists.txt

@@ -51,10 +51,16 @@ else()
             linux/opener_linux.cpp
             process/fork_pool.cpp
     )
+    # GLib's GDBus replaces sd-bus for portal calls: Ubuntu 24.04's xdg-dbus-proxy
+    # mangles sd-bus's one-shot AUTH EXTERNAL handshake but accepts GDBus's multi-step
+    # negotiation, so the app can talk to portals without --socket=session-bus.
+    # gio-unix-2.0 brings in GUnixFDList for file-descriptor passing.
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(gio REQUIRED IMPORTED_TARGET gio-2.0 gio-unix-2.0)
     target_link_libraries(
         backend
         PRIVATE
-            SDBusCpp::sdbus-c++
+            PkgConfig::gio
     )
 endif()