feat: show single-pane diffs for added deleted and renamed files

docs/editing.md

@@ -222,11 +222,11 @@ The floating selector has **Revisions / Bookmarks** tabs for jj, or **Commits /
 
 Remote references such as `some-bookmark@origin` appear from remote advertisements, including refs never fetched locally. Selecting one retrieves missing content into a temporary comparison repository. **Load history from origin** (or another configured remote) in Revisions/Commits imports searchable remote history without advancing the selection stage. These operations may require network access and the repository's existing credentials; errors stay in the selector. They do not update active refs, snapshot jj's working copy, or change the checkout.
 
-The comparison has Before on the left, After on the right, and the changed-file explorer **docked on the right**. Before and historical/remote After snapshots are read-only. Selecting **Working checkout** as After binds eligible regular UTF-8 files to normal editor buffers, reusing already-open dirty buffers and their undo history. Focus After to use native editing, selections, search, completion, undo/redo, and `:w`. Removed files, binary files, symlinks, and submodules remain read-only. Closing the diff keeps its buffers and unsaved edits.
+The changed-file explorer is **docked on the right**. Modified files show Before on the left and After on the right. Added files show only After, using the full text workspace; deleted files show only Before. Rename-only files show one empty pane, with the old and new paths in the explorer; renames with text or final-newline changes retain the split view. Before and historical/remote After snapshots are read-only. Selecting **Working checkout** as After binds eligible regular UTF-8 files to normal editor buffers, reusing already-open dirty buffers and their undo history. Focus After to use native editing, selections, search, completion, undo/redo, and `:w`. Removed files, rename-only files, binary files, symlinks, and submodules remain read-only. Closing the diff keeps its buffers and unsaved edits.
 
-Use the ordinary **file-picker/file-explorer actions and bindings**: Space `o` opens a floating picker, Space `e` opens/focuses the docked explorer, and Ctrl+w closes the focused picker/explorer and reclaims its width. Remapped bindings work too; Ctrl+e is no longer reserved by the diff. The changed-path catalog retains A/M/D/R markers and the normal compact tree, filtering, folder expansion, and configurable `tree`/`selection` navigation. It includes removed and historical paths without scanning the working directory. Enter toggles a folder or opens the selected comparison file and focuses Before. While the explorer is hidden, Tab/Shift+Tab cycles only between the two text panes.
+Use the ordinary **file-picker/file-explorer actions and bindings**: Space `o` opens a floating picker, Space `e` opens/focuses the docked explorer, and Ctrl+w closes the focused picker/explorer and reclaims its width. Remapped bindings work too; Ctrl+e is no longer reserved by the diff. The changed-path catalog retains A/M/D/R markers and the normal compact tree, filtering, folder expansion, and configurable `tree`/`selection` navigation. It includes removed and historical paths without scanning the working directory. Enter toggles a folder or opens the selected comparison file and focuses its first visible text pane: After for added files, otherwise Before. While the explorer is hidden, Tab/Shift+Tab cycles between visible text panes only; a single-pane view keeps its focus.
 
-File rows show colored **A** (added, green), **M** (modified, yellow), **D** (removed, red), or **R** (renamed, cyan) markers in Tree and List views, including filtered results. Rename rows show the new name followed by `← old/path`; directories have no file-status marker. Ordinary file exploration remains unannotated.
+File rows show colored **A** (added, green), **M** (modified, yellow), **D** (removed, red), or **R** (renamed, cyan) markers in Tree and List views, including filtered results. Rename rows show `R old/path -> new/path`; directories have no file-status marker. Ordinary file exploration remains unannotated.
 
 Text panes show change excerpts with **10 unchanged lines above and below** each change, preserving original file line numbers. Overlapping or touching excerpts merge; omitted stretches show an unchanged-line count in both panes. Files with only metadata changes show their notice or “No text changes” rather than unrelated source.
 
@@ -240,7 +240,7 @@ Changed text rows use muted red backgrounds in Before and muted green background
 
 Missing counterparts use adjacent muted `╱` diagonals (U+2571, box drawings light diagonal) on the normal terminal background, one per column. Unlike the text slash `/`, this glyph is designed to reach cell corners so diagonals can join end to end across successive rows. Pixel-perfect joins depend on the terminal's font and line-spacing rendering. Actual empty source lines retain their normal/change background and are not hatched.
 
-In Normal mode, Tab/Shift+Tab cycles focus between Files, Before, and After. Read-only text panes use Up/Down or Ctrl+j/k for shared vertical scrolling, Left/Right or Ctrl+h/l for independent horizontal scrolling, and Home/End for the first/last displayed row; editable After uses normal buffer motions. Wheel input over text panes scrolls both panes without moving the editable caret; over Files it navigates visible tree rows without opening them. Escape cancels modes, prompts, or filtering, or returns picker focus to Before; **it never closes the diff**. Use **`:diff.close`**, find `diff.close` in the palette, or bind **`config.core.diff.close`** to leave the comparison explicitly. The dotted command is intentional; there is no `:diffclose` alias.
+In Normal mode, Tab/Shift+Tab cycles focus between Files and the visible text panes, skipping absent panes. Read-only text panes use Up/Down or Ctrl+j/k for shared vertical scrolling, Left/Right or Ctrl+h/l for independent horizontal scrolling, and Home/End for the first/last displayed row; editable After uses normal buffer motions. Wheel input over text panes scrolls the visible panes without moving the editable caret; over Files it navigates visible tree rows without opening them. Escape cancels modes, prompts, or filtering, or returns picker focus to the first visible text pane; **it never closes the diff**. Use **`:diff.close`**, find `diff.close` in the palette, or bind **`config.core.diff.close`** to leave the comparison explicitly. The dotted command is intentional; there is no `:diffclose` alias.
 
 Binary data, missing final newlines, permission/type changes, symlink targets, and submodule pointers have explicit notices. Symlinks are not followed and submodule contents are not traversed. jj conflicts use jj's file-content projection and carry conflict notices; ordinary files remain readable. Identical-content moves are shown as renames; modified moves appear as an added and removed file.