feat(nosignal): CachyOS repo toggle + wire Quick Settings placebos

- CachyRepoToggleRow.qml (Settings -> Services): sudoless CachyOS optimized
  repos + linux-cachyos kernel switch, auto-tier (v4>v3); polls
  nosignal-cachy-repo status, runs enable/disable in a floating kitty. Inserted
  after SudoToggleRow in ServicesPage.qml.
- NsQuickSettings.qml: Night Light now drives hyprsunset (tile bound to the real
  pgrep'd process, not a flag); Airplane drives nmcli + bluetoothctl and binds to
  real radio state; VPN placebo tile removed (no backend).

Both built + live-tested on the reference box (06-17 PM). Helper script, sudoers
and hyprsunset dep ship in the nosignal builder.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

modules/nexus/common/CachyRepoToggleRow.qml

@@ -0,0 +1,73 @@
+// CachyRepoToggleRow.qml (NoSignal) — Settings -> Services toggle to enable /
+// disable the CachyOS pacman repositories. Auto-detects the best x86-64 microarch
+// tier the CPU supports (v4 > v3). Live state polls `nosignal-cachy-repo status`
+// (no root). enable/disable run in a floating terminal so the pacman/download
+// output stays visible; the grant is passwordless via sudo -n
+// (/etc/sudoers.d/02-nosignal-cachy). enable adds repos, converts userspace to
+// the optimized builds (pacman -Suu, pacman pinned stock), and installs the
+// linux-cachyos kernel; disable reverts to stock and removes the cachy kernel
+// (keeping stock `linux` bootable). A reboot switches the running kernel.
+//
+// Untracked file under modules/nexus/common — auto-discovered as the type
+// `CachyRepoToggleRow` via `import qs.modules.nexus.common`. Survives caelestia
+// upgrades; pairs with the one-line insert in ServicesPage.qml.
+import QtQuick
+import Quickshell.Io
+import qs.modules.nexus.common
+
+ToggleRow {
+    id: root
+
+    property bool repoOn: false   // NB: not `enabled` (reserved Item property)
+
+    text: qsTr("CachyOS repositories")
+    subtext: repoOn
+        ? qsTr("On — CachyOS optimized builds + linux-cachyos kernel (reboot to run it)")
+        : qsTr("Switch to CachyOS optimized builds + linux-cachyos kernel (reboot after)")
+
+    onToggled: {
+        if (checked)
+            enableProc.running = true;
+        else
+            disableProc.running = true;
+        reconcile.restart();
+    }
+
+    // --- live state -----------------------------------------------------------
+    Process {
+        id: statusProc
+        command: ["/usr/local/bin/nosignal-cachy-repo", "status"]
+        stdout: StdioCollector {
+            onStreamFinished: {
+                root.repoOn = text.trim() === "enabled";
+                root.checked = root.repoOn;   // drive switch from real state
+            }
+        }
+    }
+
+    // --- actions (passwordless; shown in a terminal for pacman output) ---------
+    Process {
+        id: enableProc
+        command: ["kitty", "--class", "TUI.float", "-e", "sh", "-c", "sudo -n /usr/local/bin/nosignal-cachy-repo enable; printf '\\nPress Enter to close...'; read _"]
+        onExited: reconcile.restart()
+    }
+    Process {
+        id: disableProc
+        command: ["kitty", "--class", "TUI.float", "-e", "sh", "-c", "sudo -n /usr/local/bin/nosignal-cachy-repo disable; printf '\\nPress Enter to close...'; read _"]
+        onExited: reconcile.restart()
+    }
+
+    // --- polling --------------------------------------------------------------
+    Timer {
+        interval: 5000
+        repeat: true
+        running: true
+        triggeredOnStart: true
+        onTriggered: statusProc.running = true
+    }
+    Timer {
+        id: reconcile
+        interval: 2000
+        onTriggered: statusProc.running = true
+    }
+}

modules/nexus/pages/ServicesPage.qml

@@ -216,6 +216,11 @@ PageBase {
             Layout.fillWidth: true
         }
 
+        // NoSignal: CachyOS repos enable/disable (sudoless, auto-tier)
+        CachyRepoToggleRow {
+            Layout.fillWidth: true
+        }
+
         SelectRow {
             Layout.fillWidth: true
             last: true

modules/nsbar/panels/NsQuickSettings.qml

@@ -3,10 +3,13 @@ pragma ComponentBehavior: Bound
 // NoSignal Quick Settings popout (off the media / battery pill). Avatar + user +
 // uptime + power button; 2-col toggle grid; brightness + volume sliders; media
 // card. Wired to the real services (Network, Bluetooth, Notifs, Audio,
-// Brightness, Players); Night Light / Airplane / VPN are stateful toggles for now.
+// Brightness, Players). Night Light drives hyprsunset; Airplane drives the
+// NetworkManager + Bluetooth radios. (VPN tile removed pending a real backend.)
 
 import QtQuick
 import QtQuick.Layouts
+import Quickshell
+import Quickshell.Io
 import Quickshell.Bluetooth
 import qs.services
 import qs.utils
@@ -20,6 +23,35 @@ NsPanel {
 
     readonly property var brightMon: Brightness.monitors[0] ?? null
 
+    // Night Light state tracks the real hyprsunset process rather than a local
+    // flag, so the tile stays correct across shell reloads or changes made
+    // elsewhere. Seeded on load (probe runs immediately), reconciled on a timer,
+    // and re-checked right after a toggle.
+    property bool nightLightOn: false
+
+    Process {
+        id: nightProbe
+        command: ["pgrep", "-x", "hyprsunset"]
+        running: true
+        stdout: StdioCollector {
+            onStreamFinished: root.nightLightOn = text.trim().length > 0
+        }
+    }
+
+    Timer {
+        interval: 3000
+        running: true
+        repeat: true
+        onTriggered: nightProbe.running = true
+    }
+
+    Timer {
+        id: nightRefresh
+        interval: 500
+        repeat: false
+        onTriggered: nightProbe.running = true
+    }
+
     // ── Header ───────────────────────────────────────────────────────────
     RowLayout {
         Layout.fillWidth: true
@@ -128,21 +160,31 @@ NsPanel {
             icon: "nightlight"
             label: "Night Light"
             sub: on ? "Warm 3500K" : "Off"
-            onToggled: on = !on
+            on: root.nightLightOn
+            onToggled: {
+                if (root.nightLightOn)
+                    Quickshell.execDetached(["pkill", "-x", "hyprsunset"]);
+                else
+                    Quickshell.execDetached(["sh", "-c", "pkill -x hyprsunset; hyprsunset -t 3500"]);
+                nightRefresh.restart();
+            }
         }
         QSToggle {
             id: airTog
             icon: "airplanemode_active"
             label: "Airplane"
-            sub: on ? "On" : "Off"
-            onToggled: on = !on
-        }
-        QSToggle {
-            id: vpnTog
-            icon: "vpn_key"
-            label: "VPN"
-            sub: on ? "On" : "Off"
-            onToggled: on = !on
+            // Reflects the real radio state: airplane is "On" when both Wi-Fi and
+            // Bluetooth are down. Network.wifiEnabled tracks nmcli; the adapter
+            // tracks BlueZ, so the tile self-corrects if radios change elsewhere.
+            readonly property bool radiosOff: !Network.wifiEnabled && !(Bluetooth.defaultAdapter?.enabled ?? false)
+            sub: radiosOff ? "On" : "Off"
+            on: radiosOff
+            onToggled: {
+                if (radiosOff)
+                    Quickshell.execDetached(["sh", "-c", "nmcli radio all on; bluetoothctl power on"]);
+                else
+                    Quickshell.execDetached(["sh", "-c", "nmcli radio all off; bluetoothctl power off"]);
+            }
         }
     }