feat(gui): restore folder places and add keyboard Back

Back, Forward and Up in My files restore the folder's scroll offset and
selection as they were when it was left; opening a folder any other way
still starts at the top.

Closing the photo viewer scrolls the grid to the photo it showed last.

Alt+Left and Backspace go back a level in Shared with me and Computers
and leave an open album or place; Escape leaves an album or place too,
after ending selection mode. The shortcuts window lists it.

A fresh Photos load, or leaving the grid for Albums or Places, ends a
scrubber jump that was still paging.

docs/CHANGELOG.md

@@ -74,6 +74,11 @@ Existing folders stay device backups. Older builds cannot open the upgraded data
   tell photos apart by their thumbnail. Ctrl+scroll, Ctrl+plus, Ctrl+minus and Ctrl+0
   change it too, and the size is remembered between runs.
 
+- **Back takes you to where you were.** Back, Forward and Up in My files return to a folder
+  scrolled where it was left, with the same items selected, and closing the photo viewer scrolls
+  the grid to the photo it was showing. Alt+Left and Backspace go back a level in Shared with me
+  and Computers and leave an open album or place in Photos, as Escape does too.
+
 ### Changed
 
 - **`proton-sdk` and `proton-drive-rs` 0.11.0.** Timestamps are converted where they enter
@@ -131,6 +136,9 @@ Existing folders stay device backups. Older builds cannot open the upgraded data
 - **A search in My files stays.** It was replaced by the folder's listing whenever files
   changed, on refresh and on coming back to the page, while the query stayed in the box.
 
+- **A date jump in Photos stops when you look elsewhere.** A jump still loading the timeline
+  kept going after another filter, album or place was opened.
+
 ## [3.7.0] — 2026-11-02
 
 Schema: **44**, unchanged.