hyprland: Fix mouse binds, hl.bindm does not exist

Hyprland's lua API only registers hl.bind; there is no separate
hl.bindm. The settings.bindm key rendered as a literal hl.bindm(...)
call, which errored with "attempt to call a nil value" at runtime.
Fold the mouse binds into settings.bind with { mouse = true }, per
the wiki's own example config.

hosts/pinwheel/modules/hyprland/default.nix

@@ -386,10 +386,9 @@ in
                   (lib.generators.mkLuaInline ''hl.dsp.exec_cmd("${magnifier} --reset")'')
                 ];
               }
-            ];
 
-          bindm = [
-            # mouse movements
+              # mouse movements: hyprland's lua API has no separate `bindm`,
+              # mouse binds are plain `hl.bind` with `{ mouse = true }`.
               {
                 _args = [
                   "${mod} + mouse:272" # left click