Align lint fixes with main and resolve merge conflicts

- Convert biome-ignore to oxlint-disable-next-line across client app
- Fix no-base-to-string with type narrowing instead of suppressions
- Fix no-floating-promises with fireAndForget() in proxy app
- Fix restrict-template-expressions with String() wrapping
- Resolve leftover merge conflict markers in manager.rs
- Remove duplicate cmd_plugin_init_errors from lib.rs
- Add graphql as explicit dependency in yaak-client

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/yaak-client/components/Sidebar.tsx

@@ -317,7 +317,7 @@ function Sidebar({ className }: { className?: string }) {
     "sidebar.selected.delete",
     useCallback(() => {
       const items = getSelectedTreeModels();
-      if (items) handleDeleteSelected(items);
+      if (items) void handleDeleteSelected(items);
     }, [getSelectedTreeModels, handleDeleteSelected]),
     { enable: treeHasFocus },
   );