Fold thirty-one settings pages into fifteen categories with tabs

The sidebar was a flat scan of thirty-one rows; now it reads like a
settings app. Multi-subject categories (Input, Network & Sharing,
Applications, Users & Accounts, Privacy & Security, System) carry an
Appearance-style tab strip above the page, drawn by the shell so the
leaf pages themselves are untouched. The taxonomy lives in one new
file, services/SettingsRoutes.qml; the sidebar, the strip, route
validation, search breadcrumbs, and both generators derive from it.

ShellState.settingsPage still holds leaf ids, so every deep link, IPC
call, and search result keeps working — and now lands on the exact
tab. Dictation moves out of Sound onto its own page under Input, with
a handoff back to Sound for the microphone. The strip scrolls when
System's nine tabs outgrow a tiled window. All 161 contracts pass.

Claude-Session: https://claude.ai/code/session_01Ms2FbjQy31TVf3CEvQhGM8

config/dot/quickshell/modules/settings/SettingsShell.qml

@@ -95,11 +95,39 @@ Rectangle {
         color: Theme.alpha(Theme.fg, 0.06)
     }
 
+    // The tab strip for the current category, rendered above the page so the
+    // leaf pages themselves stay untouched by the grouping. A category with a
+    // single subject earns no strip.
+    readonly property var categoryTabs: SettingsRoutes.tabsFor(ShellState.settingsPage)
+
+    Item {
+        id: categoryStrip
+
+        readonly property bool shown: root.categoryTabs.length > 1
+
+        anchors.left: sidebar.right
+        anchors.right: parent.right
+        anchors.top: titlebar.bottom
+        anchors.leftMargin: 34
+        anchors.rightMargin: 34
+        height: shown ? 48 : 0
+        visible: shown
+
+        SettingsTabs {
+            anchors.left: parent.left
+            anchors.right: parent.right
+            anchors.bottom: parent.bottom
+            tabs: root.categoryTabs.map(tab => ({ value: tab.page, label: tab.label }))
+            current: ShellState.settingsPage
+            onSelected: value => ShellState.openSettings(value)
+        }
+    }
+
     Loader {
         id: pageLoader
         anchors.left: sidebar.right
         anchors.right: parent.right
-        anchors.top: titlebar.bottom
+        anchors.top: categoryStrip.bottom
         anchors.bottom: parent.bottom
         sourceComponent: {
             switch (ShellState.settingsPage) {
@@ -114,6 +142,7 @@ Rectangle {
             case "screen-intelligence": return screenIntelligencePage;
             case "shortcuts": return shortcutsPage;
             case "mouse": return mousePage;
+            case "dictation": return dictationPage;
             case "privacy": return privacyPage;
             case "region": return regionPage;
             case "accounts": return onlineAccountsPage;
@@ -192,6 +221,7 @@ Rectangle {
     Component { id: screenIntelligencePage; ScreenIntelligencePage {} }
     Component { id: shortcutsPage; ShortcutsPage {} }
     Component { id: mousePage; MousePage {} }
+    Component { id: dictationPage; DictationPage {} }
     Component { id: privacyPage; PrivacyPage {} }
     Component { id: regionPage; RegionPage {} }
     Component { id: onlineAccountsPage; OnlineAccountsPage {} }