Merge pull request #659: feat(file-viewer): resize and expand the window, back/forward between previewed files

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/wiki/Keyboard-Shortcuts.md

@@ -57,11 +57,12 @@ default. See [Tile Grid](Tile-Grid).
 
 ## Everything else
 
-| Shortcut       | Action                          |
-| -------------- | ------------------------------- |
-| `Ctrl+Shift+V` | Toggle voice input.              |
-| `Ctrl+?`       | Shortcut reference overlay.      |
-| `Escape`       | Close panels and modals.         |
+| Shortcut          | Action                                                       |
+| ----------------- | ------------------------------------------------------------ |
+| `Ctrl+Shift+V`    | Toggle voice input.                                          |
+| `Ctrl+?`          | Shortcut reference overlay.                                  |
+| `Escape`          | Close panels and modals.                                     |
+| `Alt+←` / `Alt+→` | File Viewer window: back / forward between previewed files.  |
 
 ## Rebinding
 

docs/wiki/Working-With-Files.md

@@ -27,6 +27,11 @@ stream rather than server memory). Sensitive paths (`.env`, anything
 matching credentials, `~/.ssh`, AWS credentials) are blocked from download, and SVG and HTML
 are served as downloads rather than rendered, so they cannot execute in the page.
 
+The preview window has **Back** and **Forward** buttons (also `Alt+←` and `Alt+→`) once you
+have opened a second file, so a link into another document is no longer one way. **Expand**
+fills the screen and is remembered per device, and the corner grip resizes the window. On a
+phone the window is always full screen, so Expand and the grip are hidden there.
+
 Closing the preview pauses and unloads any playing media. A video that keeps playing after
 you close the panel means you are on an old version.