Added distro logo (for SidePanel widget)

BarTab: add toggle for distro logo replacement
DistroLogoService: handle all logo detection logic
SidePanelToggle: add support for distro logo
WidgetLoader: fix small issue with with screen null warning

Services/DistroLogoService.qml

@@ -0,0 +1,94 @@
+pragma Singleton
+
+import QtQuick
+import Quickshell
+import Quickshell.Io
+import qs.Commons
+
+Singleton {
+  id: root
+
+  // Public properties
+  property string osPretty: ""
+  property string osLogo: ""
+
+  // Internal helpers
+  function buildCandidates(name) {
+    const n = (name || "").trim()
+    if (!n)
+      return []
+
+    const sizes = ["512x512", "256x256", "128x128", "64x64", "48x48", "32x32", "24x24", "22x22", "16x16"]
+    const exts = ["svg", "png"]
+    const candidates = []
+
+    // pixmaps
+    for (const ext of exts) {
+      candidates.push(`/usr/share/pixmaps/${n}.${ext}`)
+    }
+
+    // hicolor scalable and raster sizes
+    candidates.push(`/usr/share/icons/hicolor/scalable/apps/${n}.svg`)
+    for (const s of sizes) {
+      for (const ext of exts) {
+        candidates.push(`/usr/share/icons/hicolor/${s}/apps/${n}.${ext}`)
+      }
+    }
+
+    // Generic icon themes under /usr/share/icons (common cases)
+    for (const ext of exts) {
+      candidates.push(`/usr/share/icons/${n}.${ext}`)
+      candidates.push(`/usr/share/icons/${n}/${n}.${ext}`)
+      candidates.push(`/usr/share/icons/${n}/apps/${n}.${ext}`)
+    }
+
+    return candidates
+  }
+
+  function resolveLogo(name) {
+    const all = buildCandidates(name)
+    if (all.length === 0)
+      return
+
+    const script = all.map(p => `if [ -f "${p}" ]; then echo "${p}"; exit 0; fi`).join("; ") + "; exit 1"
+    probe.command = ["sh", "-c", script]
+    probe.running = true
+  }
+
+  // Read /etc/os-release and trigger resolution
+  FileView {
+    id: osInfo
+    path: "/etc/os-release"
+    onLoaded: {
+      try {
+        const lines = text().split("\n")
+        const val = k => {
+          const l = lines.find(x => x.startsWith(k + "="))
+          return l ? l.split("=")[1].replace(/"/g, "") : ""
+        }
+        root.osPretty = val("PRETTY_NAME") || val("NAME")
+        const logoName = val("LOGO")
+        if (logoName)
+        resolveLogo(logoName)
+      } catch (e) {
+        Logger.warn("DistroLogoService", "failed to read os-release", e)
+      }
+    }
+  }
+
+  Process {
+    id: probe
+    onExited: code => {
+      const p = String(stdout.text || "").trim()
+      if (code === 0 && p) {
+        root.osLogo = `file://${p}`
+        Logger.log("DistroLogoService", "found", root.osLogo)
+      } else {
+        root.osLogo = ""
+        Logger.warn("DistroLogoService", "none found")
+      }
+    }
+    stdout: StdioCollector {}
+    stderr: StdioCollector {}
+  }
+}