refactor: add SystemStats singleton + nova-stats daemon for cpu/mem polling

modules/Cpu.qml

@@ -1,5 +1,4 @@
 import QtQuick
-import Quickshell.Io
 import "." as M
 
 M.BarSection {
@@ -7,7 +6,7 @@ M.BarSection {
     spacing: Math.max(1, M.Theme.moduleSpacing - 2)
     tooltip: ""
 
-    property int usage: 0
+    property int usage: M.SystemStats.cpuUsage
     Behavior on usage {
         NumberAnimation {
             duration: 400
@@ -15,7 +14,7 @@ M.BarSection {
         }
     }
 
-    property real freqGhz: 0
+    property real freqGhz: M.SystemStats.cpuFreqGhz
     Behavior on freqGhz {
         NumberAnimation {
             duration: 400
@@ -23,115 +22,11 @@ M.BarSection {
         }
     }
 
-    property var _prev: null
-    property var _corePrev: []
-    property var _coreUsage: []
-    property var _coreFreq: []
-    property var _coreHistory: []  // array of arrays, last 16 samples per core
-    property var _coreMaxFreq: [] // max freq in GHz per core, from cpufreq
-    property var _coreTypes: []   // "Performance" or "Efficiency" per core
-
-    FileView {
-        id: stat
-        path: "/proc/stat"
-        onLoaded: {
-            const lines = text().split("\n");
-
-            // Aggregate
-            const agg = lines[0].trim().split(/\s+/).slice(1).map(Number);
-            const idle = agg[3] + agg[4];
-            const total = agg.reduce((a, b) => a + b, 0);
-            if (root._prev) {
-                const dIdle = idle - root._prev.idle;
-                const dTotal = total - root._prev.total;
-                if (dTotal > 0)
-                    root.usage = Math.round((1 - dIdle / dTotal) * 100);
-            }
-            root._prev = {
-                idle,
-                total
-            };
-
-            // Per-core
-            const coreLines = lines.filter(l => /^cpu\d+\s/.test(l));
-            const newUsage = [];
-            const newPrev = root._corePrev.length === coreLines.length ? root._corePrev : Array(coreLines.length).fill(null);
-            for (let i = 0; i < coreLines.length; i++) {
-                const f = coreLines[i].trim().split(/\s+/).slice(1).map(Number);
-                const ci = f[3] + f[4];
-                const ct = f.reduce((a, b) => a + b, 0);
-                if (newPrev[i]) {
-                    const di = ci - newPrev[i].idle;
-                    const dt = ct - newPrev[i].total;
-                    newUsage.push(dt > 0 ? Math.round((1 - di / dt) * 100) : 0);
-                } else {
-                    newUsage.push(0);
-                }
-                newPrev[i] = {
-                    idle: ci,
-                    total: ct
-                };
-            }
-            root._coreUsage = newUsage;
-            root._corePrev = newPrev;
-
-            // Update sparkline history
-            const histLen = 16;
-            const oldH = root._coreHistory;
-            const newH = [];
-            for (let i = 0; i < newUsage.length; i++) {
-                const prev = i < oldH.length ? oldH[i] : [];
-                const next = prev.concat([newUsage[i]]);
-                newH.push(next.length > histLen ? next.slice(next.length - histLen) : next);
-            }
-            root._coreHistory = newH;
-        }
-    }
-
-    FileView {
-        id: cpuinfo
-        path: "/proc/cpuinfo"
-        onLoaded: {
-            const lines = text().split("\n").filter(l => l.startsWith("cpu MHz"));
-            if (lines.length === 0)
-                return;
-            const freqs = lines.map(l => parseFloat(l.split(":")[1]) / 1000);
-            root.freqGhz = freqs.reduce((a, b) => a + b, 0) / freqs.length;
-            root._coreFreq = freqs;
-        }
-    }
-
-    // Read per-core max freq once at init
-    Process {
-        running: true
-        command: ["sh", "-c", "for f in /sys/devices/system/cpu/cpu[0-9]*/cpufreq/cpuinfo_max_freq; do [ -f \"$f\" ] && cat \"$f\" || echo 0; done 2>/dev/null"]
-        stdout: StdioCollector {
-            onStreamFinished: {
-                root._coreMaxFreq = text.trim().split("\n").filter(l => l).map(l => parseInt(l) / 1e6);
-            }
-        }
-    }
-
-    // Read P/E-core topology once at init
-    Process {
-        running: true
-        command: ["sh", "-c", "for d in /sys/devices/system/cpu/cpu[0-9]*/topology/core_type; do [ -f \"$d\" ] && cat \"$d\" || echo Performance; done 2>/dev/null"]
-        stdout: StdioCollector {
-            onStreamFinished: {
-                root._coreTypes = text.trim().split("\n").filter(l => l).map(l => l.trim());
-            }
-        }
-    }
-
-    Timer {
-        interval: M.Modules.cpu.interval || 1000
-        running: true
-        repeat: true
-        onTriggered: {
-            stat.reload();
-            cpuinfo.reload();
-        }
-    }
+    readonly property var _coreUsage: M.SystemStats.cpuCoreUsage
+    readonly property var _coreFreq: M.SystemStats.cpuCoreFreq
+    readonly property var _coreHistory: M.SystemStats.cpuCoreHistory
+    readonly property var _coreMaxFreq: M.SystemStats.cpuCoreMaxFreq
+    readonly property var _coreTypes: M.SystemStats.cpuCoreTypes
 
     property bool _pinned: false
     readonly property bool _anyHover: root._hovered || hoverPanel.panelHovered