fix(sway): restore clobbered keybindings; update foot for 1.27

Two desktop-config fixes found together:

1. Keybindings: the previous Mod+Space launcher bind wrapped the set in
   `lib.mkMerge [ { ... } (mkOptionDefault ...) ]`. A normal-priority
   definition there wins over (and discards) the home-manager module's
   default keybindings, which are at mkOptionDefault priority -- so every
   default bind (terminal Mod+Return, movement, workspaces, kill, ...) and
   even the custom swaylock/volume binds silently vanished; only Mod+Space
   survived. That is why Super+Enter opened nothing. Restore the single
   mkOptionDefault wrapper (so it merges with the module defaults) and
   override just Mod+Space via lib.mkForce to beat the module's default
   focus-mode_toggle without a same-priority conflict. Generated config
   goes from 1 bindsym back to 57.

2. foot 1.27: the bare [colors] section is deprecated in favour of
   [colors-dark], and `[cursor] color` is rejected ("not a valid option:
   color"). Move the palette to colors-dark and set the cursor colour via
   its `cursor` key ("<text> <cursor>"). `foot --check-config` now passes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lyrathorpe/home/sway.nix

@@ -120,14 +120,17 @@ in
         }
       ];
 
-      keybindings = lib.mkMerge [
-        # Bind the launcher to Mod+Space. This deliberately replaces the default
-        # Mod+Space (focus mode_toggle); a bare attrset (normal priority) wins
-        # over the module default, whereas the mkOptionDefault block below would
-        # only tie with it. Mod+d still runs the launcher too (module default).
-        { "${modifier}+space" = "exec ${menu}"; }
-        (lib.mkOptionDefault (
+      # NB: this whole set is wrapped in mkOptionDefault so it MERGES with the
+      # home-manager module's default keybindings (same priority) rather than
+      # replacing them. Do not wrap it in mkMerge with a normal-priority attr --
+      # that makes the normal-priority def win and silently drops every default
+      # bind (terminal, movement, workspaces, ...).
+      keybindings = lib.mkOptionDefault (
         {
+          # Launcher on Mod+Space. mkForce overrides the module's own default
+          # Mod+Space (focus mode_toggle); a plain value would conflict with it
+          # at equal priority. Mod+d also still runs the launcher (module default).
+          "${modifier}+space" = lib.mkForce "exec ${menu}";
           "${modifier}+l" = "exec ${pkgs.swaylock}/bin/swaylock -f";
           "Print" = "exec ${pkgs.grim}/bin/grim ~/screenshot-$(date +%F-%H%M%S).png";
           "XF86AudioRaiseVolume" = "exec ${pkgs.wireplumber}/bin/wpctl set-volume @DEFAULT_AUDIO_SINK@ 5%+";
@@ -139,8 +142,7 @@ in
           "XF86MonBrightnessUp" = "exec ${pkgs.brightnessctl}/bin/brightnessctl set 5%+";
           "XF86MonBrightnessDown" = "exec ${pkgs.brightnessctl}/bin/brightnessctl set 5%-";
         }
-        ))
-      ];
+      );
     };
   };
 
@@ -148,8 +150,13 @@ in
   # `terminal` above still launches the same binary, now themed.
   programs.foot = {
     enable = true;
+    # foot 1.27: the bare [colors] section is deprecated in favour of
+    # [colors-dark] (the default theme), and the cursor colour moved out of
+    # [cursor] (where `color` is now rejected) into a `cursor` key here, written
+    # "<text> <cursor>" (man foot.ini(5): "ff0000 00ff00" => green cursor, red
+    # text). Only colors-dark is needed; we never set initial-color-theme=light.
     settings = {
-      colors = {
+      "colors-dark" = {
         background = ctp.base;
         foreground = ctp.text;
         regular0 = ctp.surface1;
@@ -170,8 +177,8 @@ in
         bright7 = ctp.subtext0;
         "selection-foreground" = ctp.base;
         "selection-background" = ctp.rosewater;
+        cursor = "${ctp.base} ${ctp.rosewater}";
       };
-      cursor.color = "${ctp.base} ${ctp.rosewater}";
     };
   };