feat(settings): add Mouse & Touchpad settings tab for Niri (#2905)

* feat(settings): add Mouse & Trackpad settings tab

* style(settings): clarify touchpad natural scroll description

* chore(settings): update settings search index

* refactor(settings): unify Mouse & Trackpad terminology to Mouse & Touchpad

* feat(setup): deploy default dms/input.kdl on setup

* style(niri): restore include section comment in base config template

* refactor(niri): remove redundant input block from base config template

* refactor(niri): restore keyboard and non-mouse input config to base template

* feat(settings): add touchpad disable-on-external-mouse toggle

* feat(settings): add left-handed, scroll-factor and dwt options

* feat(settings): add middle-emulation, scroll-method, tap-and-drag and drag-lock options

* refactor(settings): re-order mouse and touchpad UI options logically

core/cmd/dms/commands_config.go

@@ -40,6 +40,7 @@ var resolveIncludeCmd = &cobra.Command{
 				"layout.kdl",
 				"outputs.kdl",
 				"binds.kdl",
+				"input.kdl",
 				"cursor.conf",
 				"layout.conf",
 				"outputs.conf",

core/cmd/dms/commands_setup.go

@@ -143,6 +143,10 @@ var dmsConfigSpecs = map[string]dmsConfigSpec{
 		niriFile:    "alttab.kdl",
 		niriContent: func(_ string) string { return config.NiriAlttabConfig },
 	},
+	"input": {
+		niriFile:    "input.kdl",
+		niriContent: func(_ string) string { return config.NiriInputConfig },
+	},
 	"outputs": {
 		niriFile:     "outputs.kdl",
 		hyprFile:     "outputs.lua",