feat: rice selector with two-step rice+wallpaper picker

Adds a dedicated RiceSelector to the Quickshell launcher that lets
the user pick a rice and one of its own wallpapers in two guided
steps before applying. Triggered with "> rice " in the launcher.

Backend:
- dots-appearance list now includes wallpapers[] per rice
- dots-appearance apply supports --wallpaper <path> flag

Launcher (new):
- RiceWallpaperItem.qml: carousel item for plain string paths
- RiceSelector.qml: two-step component (rice list → wallpaper carousel)

Launcher (updated):
- ContentList: "riceSelector" state + Loader
- Content: Enter/Escape handling for both steps
- AppearanceItem: 40×22px preview.png thumbnail
- AppearancesSection: 56×32px preview.png thumbnail in Control Center

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat/rice-selector:
  feat(launcher): add preview.png thumbnails to appearance items
  feat(launcher): integrate RiceSelector into ContentList and Content
  feat(launcher): add RiceSelector two-step rice+wallpaper picker
  feat(launcher): add RiceWallpaperItem for RiceSelector carousel
  feat(launcher): expose preview and wallpapers in Appearances service
  feat(appearance): add --wallpaper flag to dots-appearance apply
  feat(appearance): add wallpapers[] array to dots-appearance list output

Author: ulises-jeremias

home/dot_config/quickshell/modules/controlcenter/appearance/sections/AppearancesSection.qml

@@ -5,6 +5,7 @@ import "../../../launcher/services"
 import qs.components
 import qs.components.controls
 import qs.components.containers
+import qs.components.images
 import qs.services
 import qs.config
 import Quickshell
@@ -65,6 +66,24 @@ CollapsibleSection {
 
                     spacing: Appearance.spacing.normal
 
+                    Loader {
+                        active: (modelData.preview ?? "") !== ""
+                        Layout.alignment: Qt.AlignVCenter
+
+                        sourceComponent: StyledClippingRect {
+                            implicitWidth: 56
+                            implicitHeight: 32
+                            radius: Appearance.rounding.small
+                            color: Colours.tPalette.m3surfaceContainer
+
+                            CachingImage {
+                                anchors.fill: parent
+                                path: modelData.preview ?? ""
+                                cache: true
+                            }
+                        }
+                    }
+
                     MaterialIcon {
                         text: Appearances.styleIcon(modelData.style || "")
                         font.pointSize: Appearance.font.size.large

home/dot_config/quickshell/modules/launcher/Content.qml

@@ -82,6 +82,24 @@ Item {
             placeholderText: qsTr("Type \"%1\" for commands").arg(Config.launcher.actionPrefix)
 
             onAccepted: {
+                if (list.showRiceSelector) {
+                    const rs = list.riceSelector;
+                    if (!rs)
+                        return;
+                    if (rs.step === "wallpapers") {
+                        const wp = rs.currentWallpaperPath;
+                        if (wp) {
+                            if (Colours.scheme === "dynamic")
+                                Wallpapers.previewColourLock = true;
+                            Quickshell.execDetached(["dots-appearance", "apply", rs.selectedRice.id, "--wallpaper", wp]);
+                            root.visibilities.launcher = false;
+                        }
+                    } else {
+                        rs.confirmCurrentRice();
+                    }
+                    return;
+                }
+
                 const currentItem = list.currentList?.currentItem;
                 if (currentItem) {
                     if (list.showWallpapers) {
@@ -104,7 +122,12 @@ Item {
             Keys.onUpPressed: list.currentList?.decrementCurrentIndex()
             Keys.onDownPressed: list.currentList?.incrementCurrentIndex()
 
-            Keys.onEscapePressed: root.visibilities.launcher = false
+            Keys.onEscapePressed: {
+                if (list.showRiceSelector && list.riceSelector?.step === "wallpapers")
+                    list.riceSelector.goBack();
+                else
+                    root.visibilities.launcher = false;
+            }
 
             Keys.onPressed: event => {
                 if (!Config.launcher.vimKeybinds)

home/dot_config/quickshell/modules/launcher/ContentList.qml

@@ -19,14 +19,16 @@ Item {
     required property int padding
     required property int rounding
 
+    readonly property bool showRiceSelector: search.text.startsWith(`${Config.launcher.actionPrefix}rice `)
     readonly property bool showWallpapers: search.text.startsWith(`${Config.launcher.actionPrefix}wallpaper `)
-    readonly property Item currentList: showWallpapers ? wallpaperList.item : appList.item
+    readonly property Item currentList: showRiceSelector ? riceSelectorLoader.item?.currentList ?? null : showWallpapers ? wallpaperList.item : appList.item
+    readonly property var riceSelector: riceSelectorLoader.item
 
     anchors.horizontalCenter: parent.horizontalCenter
     anchors.bottom: parent.bottom
 
     clip: true
-    state: showWallpapers ? "wallpapers" : "apps"
+    state: showRiceSelector ? "riceSelector" : showWallpapers ? "wallpapers" : "apps"
 
     states: [
         State {
@@ -51,6 +53,15 @@ Item {
                 root.implicitHeight: Config.launcher.sizes.wallpaperHeight
                 wallpaperList.active: true
             }
+        },
+        State {
+            name: "riceSelector"
+
+            PropertyChanges {
+                root.implicitWidth: riceSelectorLoader.item?.implicitWidth ?? Config.launcher.sizes.itemWidth
+                root.implicitHeight: Math.min(root.maxHeight, riceSelectorLoader.item?.implicitHeight ?? Config.launcher.sizes.wallpaperHeight)
+                riceSelectorLoader.active: true
+            }
         }
     ]
 
@@ -104,6 +115,21 @@ Item {
         }
     }
 
+    Loader {
+        id: riceSelectorLoader
+
+        active: false
+
+        anchors.fill: parent
+
+        sourceComponent: RiceSelector {
+            search: root.search
+            visibilities: root.visibilities
+            panels: root.panels
+            content: root.content
+        }
+    }
+
     Row {
         id: empty
 
@@ -117,7 +143,7 @@ Item {
         anchors.verticalCenter: parent.verticalCenter
 
         MaterialIcon {
-            text: root.state === "wallpapers" ? "wallpaper_slideshow" : "manage_search"
+            text: root.state === "wallpapers" ? "wallpaper_slideshow" : root.state === "riceSelector" ? "palette" : "manage_search"
             color: Colours.palette.m3onSurfaceVariant
             font.pointSize: Appearance.font.size.extraLarge
 
@@ -128,7 +154,7 @@ Item {
             anchors.verticalCenter: parent.verticalCenter
 
             StyledText {
-                text: root.state === "wallpapers" ? qsTr("No wallpapers found") : qsTr("No results")
+                text: root.state === "wallpapers" ? qsTr("No wallpapers found") : root.state === "riceSelector" ? qsTr("No appearances found") : qsTr("No results")
                 color: Colours.palette.m3onSurfaceVariant
                 font.pointSize: Appearance.font.size.larger
                 font.weight: 500