fix(tmux): visible selection colour, mouse drag copies on release

- mode-style bg=yellow,fg=black (black on a dark terminal was invisible)
- MouseDragEnd1Pane copies (pbcopy on macOS, tmux buffer elsewhere) without leaving copy-mode

tmux.conf

@@ -108,7 +108,9 @@ unbind p                                        # (pasting)
 unbind %                                        # (sp)
 unbind '"'                                      # (vs)
 unbind-key -T copy-mode-vi MouseDragEnd1Pane # (mouse setting) {{{
-#   disable "release mouse drag to copy and exit copy-mode"
+#   stock binding = "release the drag: copy AND leave copy-mode", which loses
+#   the selection on screen. Rebound below (clipboard section) as copy without
+#   leaving, so a drag is enough and y stays available.
 #   ref: https://github.com/tmux/tmux/issues/140
 # }}}
 
@@ -142,9 +144,10 @@ bind -Tcopy-mode-vi 'v' send -X begin-selection    # bind vi-like visual mode
 # Clipboard: pbcopy/pbpaste on macOS. Elsewhere tmux's own buffer, which tmux
 # also hands to the terminal through OSC 52 (set-clipboard), so it reaches the
 # local clipboard over ssh. xsel/xclip dropped: headless servers have no X.
+# Releasing a mouse drag copies too (selection kept on screen, copy-mode stays).
 if-shell 'command -v pbcopy >/dev/null' \
-    'bind -Tcopy-mode-vi y send -X copy-pipe-and-cancel pbcopy ; bind p run "pbpaste | tmux load-buffer - ; tmux paste-buffer"' \
+    'bind -Tcopy-mode-vi y send -X copy-pipe-and-cancel pbcopy ; bind -Tcopy-mode-vi MouseDragEnd1Pane send -X copy-pipe-no-clear pbcopy ; bind p run "pbpaste | tmux load-buffer - ; tmux paste-buffer"' \
-    'bind -Tcopy-mode-vi y send -X copy-selection-and-cancel ; bind p paste-buffer'
+    'bind -Tcopy-mode-vi y send -X copy-selection-and-cancel ; bind -Tcopy-mode-vi MouseDragEnd1Pane send -X copy-selection-no-clear ; bind p paste-buffer'
 bind-key -Tcopy-mode-vi Escape send -X cancel                  # cancel v mode
 bind-key -Tcopy-mode-vi ^v send -X rectangle-toggle            # cancel v mode
 
@@ -236,7 +239,7 @@ set -g @resurrect-dir "$XDG_CACHE_HOME/tmux/$TMUX_SOCKET_NAME"
 # Status Bar:                                                               {{{
 # ----------
 
-set -wg mode-style bg=black,fg=brightwhite
+set -wg mode-style bg=yellow,fg=black          # selection: same accent as the status bar
 set-window-option -g window-status-separator ''
 set -g status-position bottom
 set -g status-left-length 42