Merge PR #2366: LRC-LIB-LIBFOLDERS: Synchronize Folder says a folder is up to date, with one Close

docs/parity-checklist.md: header and revision rows from both sides; LRC-LIB-LIBFOLDERS row takes both wording changes

docs/control-protocol.md

@@ -76,7 +76,7 @@ filmstrip is visible.
 | `ui.scroll` | `{dx, dy, cmd?, ctrl?, shift?, alt?}` | Wheel / two-finger scroll at the current pointer; pans over the image, modifier-scroll zooms |
 | `ui.zoom` | `{factor}` | Pinch zoom at the current pointer (positive scale multiplier; 1 = unchanged). Position it first with `ui.move` or `ui.hoverWidget` |
 | `ui.set` | partial UI state, e.g. `{"view": "detail"}` | Resulting UI state |
-| `ui.dialog.confirm` / `ui.dialog.cancel` | — | Close the open dialog |
+| `ui.dialog.confirm` / `ui.dialog.cancel` | — | Close the open dialog (confirm runs its action; Synchronize Folder on a folder that is up to date answers `{"upToDate": true}` and starts nothing) |
 | `ui.resize` | `{width, height}` | Resize the window |
 | `ui.zoomFactor` | `{factor}` | Set the interface scale (0.5–3; egui's zoom keys are off, Cmd+= / Cmd+- zoom the photo) |
 | `ui.screenshot` | `{path?, headless?}` | `{path, width, height}` once the frame (with finished renders) is captured. `headless: true` draws the UI on the CPU (no compositor needed); a windowed capture that gets no frame within 2 s falls back to headless automatically. While the loupe still waits for a render, `ui.widgets {filter: "loupe:rendering"}` lists its "Rendering…" pill; `loupe:renderFailed` is the pill saying a render failed behind a stand-in; Compare and Reference panes have their own (`compare:rendering:<pane>`, `compare:renderFailed:<pane>`) |

docs/whats-new.md

@@ -2,6 +2,12 @@
 
 ## 2026-10-19
 
+### Synchronize Folder on a folder that is up to date
+- When the scan finds nothing to import, relink, remove or read, the Synchronize Folder dialog says the library is up
+  to date with the folder and has one Close button. It used to show four greyed choices, two of them still ticked,
+  and a Synchronize button that started a job with nothing to do. Files it skipped (already in the library elsewhere,
+  or unreadable) are still listed.
+
 ### Hidden Local locations come back one at a time
 - With several locations removed from Local, "Show N hidden locations" now lists them, so each comes back on its own
   (Restore All is there too). The row used to bring every hidden location back at once (issue #2114).