Saving or deleting a finding on the first page pushes a duplicate browser history entry #3666

Description

On the operation detail page, saving or deleting a finding always calls navigatePage(0), which writes an empty search string into the URL. When the page is already the first page (no offset parameter), the URL is identical, and react-router still pushes a new history entry for it.

Steps to reproduce

1. Open an operation with at least one finding while on the first findings page.
2. Save a new finding or delete an existing one.
3. Press browser Back.

Expected behavior

Back returns to the previous page. Creating or deleting a finding on the first page should not touch the history stack, since the URL does not change.

Actual behavior

Back re-renders the same operation page with the same data, because the save pushed a duplicate entry for an identical URL. Repeated saves stack one dead entry each, so leaving the page takes as many Back presses as there were saves.

The navigation should be skipped when the offset is already the one being requested; the refresh itself is driven by the existing revision bump.