Fix: Add view mode persistence for xdg-open picker modals (#1465)

* fix: Add browserPickerViewMode persistence to settings spec

The BrowserPickerModal (used by xdg-open feature) was not persisting
view mode selection between sessions. While the modal had code to save
the view mode preference, the browserPickerViewMode property was not
registered in SettingsSpec.js, preventing it from being saved to disk.

Added browserPickerViewMode and browserUsageHistory to SettingsSpec.js
to ensure user's view preference (list/grid) is properly persisted.

Fixes view mode reverting to grid after restarting DMS/QuickShell.

* fix: Add view mode persistence for both browser and file pickers

Extended the fix to include both picker modals used by xdg-open:

BrowserPickerModal (URLs):
- Added browserPickerViewMode and browserUsageHistory to SettingsSpec.js
- Already had save logic in BrowserPickerModal.qml

AppPickerModal/filePickerModal (files):
- Added appPickerViewMode and filePickerUsageHistory to SettingsSpec.js
- Added appPickerViewMode and filePickerUsageHistory properties to SettingsData.qml
- Added viewMode binding and onViewModeChanged handler to filePickerModal

Both modals now properly persist user's view preference (list/grid) and
usage history between sessions.

Fixes view mode reverting to default grid after restarting DMS/QuickShell
for both 'dms open https://...' and 'dms open file.pdf' workflows.

quickshell/Common/SettingsData.qml

@@ -274,6 +274,8 @@ Singleton {
     property string spotlightModalViewMode: "list"
     property string browserPickerViewMode: "grid"
     property var browserUsageHistory: ({})
+    property string appPickerViewMode: "grid"
+    property var filePickerUsageHistory: ({})
     property bool sortAppsAlphabetically: false
     property int appLauncherGridColumns: 4
     property bool spotlightCloseNiriOverview: true

quickshell/Common/settings/SettingsSpec.js

@@ -133,6 +133,10 @@ var SPEC = {
 
     appLauncherViewMode: { def: "list" },
     spotlightModalViewMode: { def: "list" },
+    browserPickerViewMode: { def: "grid" },
+    browserUsageHistory: { def: {} },
+    appPickerViewMode: { def: "grid" },
+    filePickerUsageHistory: { def: {} },
     sortAppsAlphabetically: { def: false },
     appLauncherGridColumns: { def: 4 },
     spotlightCloseNiriOverview: { def: true },

quickshell/DMSShell.qml

@@ -550,6 +550,11 @@ Item {
     AppPickerModal {
         id: filePickerModal
         title: I18n.tr("Open with...")
+        viewMode: SettingsData.appPickerViewMode || "grid"
+
+        onViewModeChanged: {
+            SettingsData.set("appPickerViewMode", viewMode)
+        }
 
         function shellEscape(str) {
             return "'" + str.replace(/'/g, "'\\''") + "'";