feat(hyprland): launch-or-focus binds (item 17)

nomarchy.launchOrFocus (opt-in, commented template example): each
entry gives a key that FOCUSES the app's existing window
(case-insensitive class match via jq + a "(?i)" focuswindow regex) or
launches it when none is open. One shared nomarchy-focus-or-launch
script; a bind whose command was removed from the suite fires a
"not installed" toast instead of failing silently. The same entries
render into the SUPER+? cheatsheet through prettyKeys — bind and
documentation stay one source. README row added.

Verified: V0; V1 — a scratch downstream with two entries renders both
binds (default command = lowercased class; custom mods/command/desc
honored), the script passes bash -n with a usage guard, and the
cheatsheet carries both rows. Focus behaviour needs a session -> V3
(HARDWARE-QUEUE).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

modules/home/options.nix

@@ -237,6 +237,52 @@ in
       '';
     };
 
+    launchOrFocus = lib.mkOption {
+      type = lib.types.listOf (lib.types.submodule {
+        options = {
+          key = lib.mkOption {
+            type = lib.types.str;
+            example = "B";
+            description = "The key (with `mods`) that focuses-or-launches the app.";
+          };
+          mods = lib.mkOption {
+            type = lib.types.str;
+            default = "$mod";
+            description = "Modifier string, Hyprland syntax (\"$mod\", \"$mod SHIFT\").";
+          };
+          class = lib.mkOption {
+            type = lib.types.str;
+            example = "firefox";
+            description = "Window class to focus (case-insensitive; see `hyprctl clients`).";
+          };
+          command = lib.mkOption {
+            type = lib.types.str;
+            default = "";
+            description = "Command to launch when no window matches (defaults to the class).";
+          };
+          desc = lib.mkOption {
+            type = lib.types.str;
+            default = "";
+            description = "Cheatsheet label (defaults to \"Focus or launch <command>\").";
+          };
+        };
+      });
+      default = [ ];
+      example = lib.literalExpression ''
+        [
+          { key = "B"; class = "firefox"; }
+          { key = "O"; class = "obsidian"; }
+        ]
+      '';
+      description = ''
+        Launch-or-focus binds: the key focuses the app's existing window
+        (case-insensitive class match) or launches it if none is open. Each
+        entry generates a Hyprland bind AND a SUPER+? cheatsheet row. The
+        launcher self-gates: a bind whose command isn't installed notifies
+        instead of failing silently.
+      '';
+    };
+
     displayProfiles = lib.mkOption {
       type = lib.types.attrsOf (lib.types.listOf monitorType);
       default = { };