fix(config-settings): repair diff-redraw review findings

- Print the missing exit-repaint after the inline editor's
  __cs_dispatch_draw call (was silently changed to capture-only earlier
  in the branch; this call site was missed, blanking the panel on
  commit/cancel of an inline edit).
- Hoist (count $prev_edit_frame) out of a quoted math string in the
  inline editor's per-keystroke redraw -- fish doesn't expand a command
  substitution there, so math silently errored.
- Add a >= 52 column floor to both diff-path guards: below the
  narrowest tier's own 52-column box width, lines wrap and the diff
  path's one-physical-row-per-logical-line walk corrupts the display.
- Reword a stale test comment that described panel_h as mirroring a
  hand-set constant in __cs_dispatch_draw; it derives panel_h from real
  output now.
- Declare prev_edit_frame with -l alongside edit_frame instead of a
  bare set, matching the file's convention.
- Move prev_frame's declaration to its point of use instead of an
  empty top-level placeholder, matching old_h in the same block.

functions/config-settings.fish

@@ -147,7 +147,6 @@ function config-settings --description 'Interactive TUI for managing fish config
     set -l cur_row   0
     set -l panel_h   0            # real value set by the first dispatch call below
     set -l new_frame              # captured by __cs_dispatch_draw
-    set -l prev_frame             # frame currently on screen; empty until first paint
     set -l last_cols $COLUMNS
 
     # ── Terminal setup ────────────────────────────────────
@@ -344,6 +343,7 @@ function config-settings --description 'Interactive TUI for managing fish config
                         # Full erase once to enter edit mode; per-keystroke
                         # redraws below diff against the previous edit frame.
                         set -l edit_frame (__config_settings_draw_value $cur_row $page edit "$buf")
+                        set -l prev_edit_frame
                         set -l pml (math --scale=0 "($last_cols + 78) / 2")
                         set -l eh (math --scale=0 "$panel_h * max(1, ceil($pml / $COLUMNS))")
                         printf '\e[%dA\e[J' $eh
@@ -370,15 +370,16 @@ function config-settings --description 'Interactive TUI for managing fish config
 
                             set prev_edit_frame $edit_frame
                             set edit_frame (__config_settings_draw_value $cur_row $page edit "$buf")
-                            if test (count $edit_frame) -eq (count $prev_edit_frame) -a "$COLUMNS" = "$last_cols"
+                            if test (count $edit_frame) -eq (count $prev_edit_frame) -a "$COLUMNS" = "$last_cols" -a $COLUMNS -ge 52
                                 # `| string collect` is required on each join --
                                 # see the identical note in the main loop's
                                 # diff-path call.
                                 printf '\e[%dA' (count $edit_frame)
                                 __config_settings_diff_redraw (string join \n -- $prev_edit_frame | string collect) (string join \n -- $edit_frame | string collect)
                             else
+                                set -l ph (count $prev_edit_frame)
                                 set -l pml (math --scale=0 "($last_cols + 78) / 2")
-                                set -l eh (math --scale=0 "(count $prev_edit_frame) * max(1, ceil($pml / $COLUMNS))")
+                                set -l eh (math --scale=0 "$ph * max(1, ceil($pml / $COLUMNS))")
                                 printf '\e[%dA\e[J' $eh
                                 printf '%s\n' $edit_frame
                             end
@@ -399,6 +400,7 @@ function config-settings --description 'Interactive TUI for managing fish config
                         printf '\e[%dA\e[J' $eh
                         set last_cols $COLUMNS
                         __cs_dispatch_draw
+                        printf '%s\n' $new_frame
                         set did_redraw 1
                     end
                 end
@@ -423,10 +425,10 @@ function config-settings --description 'Interactive TUI for managing fish config
         end
 
         set -l old_h $panel_h
-        set prev_frame $new_frame
+        set -l prev_frame $new_frame
         __cs_dispatch_draw
 
-        if test $panel_h -eq $old_h -a "$COLUMNS" = "$last_cols"
+        if test $panel_h -eq $old_h -a "$COLUMNS" = "$last_cols" -a $COLUMNS -ge 52
             # Diff path: geometry and width unchanged since the last frame --
             # move up without erasing, rewrite only the lines that changed.
             # `| string collect` is required on each join: command

tests/config-settings-render.fish

@@ -153,10 +153,11 @@ set -U __fish_user_dots_symlink false
 # __fish_scrollback_history_max_files: unset -> DEFAULT
 
 # ── Case emitter ──────────────────────────────────────────────────────────
-# panel_h is passed in by the caller, mirroring __cs_dispatch_draw in
-# config-settings.fish: the category list and both value pages are a fixed 16
-# lines, a sub-category page is 7 + <sub-category count>. The golden records
-# the declared height, the measured line count, and the erase sequence derived
+# panel_h is passed in by the caller, independently declaring the expected
+# height for each page so it can be cross-checked against the draw functions'
+# real output: the category list and both value pages are a fixed 16 lines, a
+# sub-category page is 7 + <sub-category count>. The golden records the
+# declared height, the measured line count, and the erase sequence derived
 # from the declared height -- so flattening the fixed/dynamic divergence, or
 # changing a page's height at all, breaks the compare three ways.
 function _cs_render_case --argument-names label panel_h