When the resolver dialog is already visible on the Missing Models tab,
showResolvedNodeModelInResolver now reuses the existing browser instead
of forcing a reload or requeuing the selection. This avoids unnecessary
UI refreshes and keeps the current view stable.
Changes:
- web/resolver/model_resolver.js: skip reopen/queue when the dialog is
already visible on the missing tab; prefer existing browser selection
- web/resolver/views/missing_browser_methods.js: support
preferExistingBrowser in selectWorkflowModelReference and center the
selected row instead of scrolling to nearest
- tests/test_downloads_tab_workflow_route.mjs: cover reuse behavior and
row-patching/centering