feature(tmux): make tmux forward csi-u sequences thus enabling shift-enter in opencode

modules/home-manager/tmux.nix

@@ -5,7 +5,7 @@ let
   #
   # Written as escapes rather than literal glyphs. These are Private Use Area
   # codepoints: they render only with a patched font, they survive copy/paste
-  # badly, and when they get stripped the loss is invisible -- the config still
+  # badly, and when they get stripped the loss is invisible, the config still
   # parses, the status bar just quietly loses its separators. Nix has no \u
   # escape of its own, but fromJSON does.
   sep = builtins.fromJSON ''
@@ -19,28 +19,27 @@ let
 in
 {
   programs.tmux = {
+    # defaults
     enable = true;
     prefix = "C-a";
     keyMode = "vi";
     mouse = true;
 
     # tmux-256color gives truecolor, italics and undercurl in nvim.
-    # screen-256color has none of them. No terminfo gymnastics needed here --
-    # unlike macOS, NixOS ships a current ncurses that has the entry.
     terminal = "tmux-256color";
 
-    # Default is 500ms. That is the lag you feel leaving insert mode in nvim,
+    # Default is 500ms. Causes lag you feel when leaving insert mode in nvim,
     # because tmux is waiting to see whether Esc starts an escape sequence.
     escapeTime = 10;
 
-    # nvim autoread / :checktime react to focus. home-manager defaults to false.
+    # nvim autoread / :checktime react to focus.
     focusEvents = true;
 
-    # Default is 2000.
+    # History limit.
     historyLimit = 50000;
 
-    # Window numbers matching the number row. Behaviour change, so opt in.
-    # baseIndex = 1;
+    # Window numbers matching the number row.
+    baseIndex = 1;
 
     extraConfig = ''
       # Status keys
@@ -49,16 +48,15 @@ in
       # Tell tmux the outer terminal can do 24-bit colour (tmux >= 3.2).
       set -sa terminal-features ",*:RGB"
 
-      # --- Shift+Enter / extended keys -----------------------------------
-      # Still the open topic; uncommenting these makes tmux forward CSI-u
-      # sequences unconditionally. Needs tmux >= 3.5 for the format option,
-      # and a `tmux kill-server` afterwards -- a config reload is not enough.
-      #set -s extended-keys always
-      #set -s extended-keys-format csi-u
-      #set -as terminal-features '*:extkeys'
+      # Shift+Enter / extended keys
+      # These make tmux forward CSI-u sequences unconditionally.
+      # Needs tmux >= 3.5 for the format option,
+      set -s extended-keys always
+      set -s extended-keys-format csi-u
+      set -as terminal-features '*:extkeys'
 
       # Status bar options
-      set -g status-interval 5   # was 1; the clock only has minute resolution
+      set -g status-interval 5
       set -g status-justify left
 
       # Clock mode
@@ -69,11 +67,9 @@ in
       set -g status-fg white
 
       # Key bindings
-      # Reload configuration. tmux.conf is a read-only symlink into the nix
-      # store, so this only picks up changes after `home-manager switch`.
       bind r source-file ~/.config/tmux/tmux.conf \; display-message "tmux.conf reloaded"
 
-      # Panel split and selection -- new panes/windows inherit the cwd
+      # Panel split and selection, new panes/windows inherit the cwd
       unbind %
       unbind '"'
       bind v split-window -v -c "#{pane_current_path}"
@@ -88,7 +84,7 @@ in
       bind k select-pane -U
       bind l select-pane -R
 
-      # Resize panes -- -r makes them repeatable, hold instead of re-prefixing
+      # Resize panes
       bind -r H resize-pane -L 5
       bind -r J resize-pane -D 5
       bind -r K resize-pane -U 5
@@ -96,7 +92,6 @@ in
 
       # Wayland clipboard integration
       # Copy selection to both clipboard (Ctrl+V / Shift+Insert) and primary (middle-click)
-      # v/C-v added: you had no way to *start* a selection from the keyboard.
       bind -T copy-mode-vi v send-keys -X begin-selection
       bind -T copy-mode-vi C-v send-keys -X rectangle-toggle
       bind -T copy-mode-vi y send-keys -X copy-pipe-and-cancel "wl-copy && wl-copy --primary"
@@ -107,7 +102,6 @@ in
       #set -g set-clipboard on
 
       # Kill commands
-      # Drop the `confirm-before -p "..."` part for the old single keystroke.
       bind q confirm-before -p "kill window #W? (y/n)" kill-window
       bind Q confirm-before -p "kill session #S? (y/n)" kill-session