refactor: delegate shell command construction to lib.js functions

Replace inline shell command building in QML with calls to
parseClipboardDetection, parseStatusResult, buildToggleCommand, and
buildCopyCommand. This centralizes sanitization logic and removes
duplicated try/catch and ternary blocks from the UI layer.

tailscalectl/TailscaleWidget.qml

@@ -66,7 +66,7 @@ PluginComponent {
 
         stdout: StdioCollector {
             onStreamFinished: {
-                root.clipboardCmd = this.text.trim()
+                root.clipboardCmd = TailscaleLib.parseClipboardDetection(this.text)
             }
         }
 
@@ -82,19 +82,11 @@ PluginComponent {
 
         stdout: StdioCollector {
             onStreamFinished: {
-                try {
+                const state = TailscaleLib.parseStatusResult(this.text)
-                    const data = JSON.parse(this.text)
+                root.isConnected = state.isConnected
-                    root.isConnected = data.BackendState === "Running"
+                root.tailscaleIP = state.tailscaleIP
-                    root.tailscaleIP = (data.Self?.TailscaleIPs?.[0]) || ""
+                root.currentExitNode = state.currentExitNode
-                    root.currentExitNode = TailscaleLib.findActiveExitNode(data.Peer || {})
+                root.peers = state.peers
-                    root.peers = TailscaleLib.parsePeers(data.Peer || {})
-                } catch (e) {
-                    root.isConnected = false
-                    root.tailscaleIP = ""
-                    root.currentExitNode = ""
-                    root.peers = []
-                    ToastService.showError("tailscalectl", "Failed to parse Tailscale status")
-                }
             }
         }
 
@@ -119,11 +111,7 @@ PluginComponent {
             ToastService.showError("tailscalectl", "Tailscale not available")
             return
         }
-        if (root.isConnected) {
+        toggleProcess.command = TailscaleLib.buildToggleCommand(root.isConnected)
-            toggleProcess.command = ["tailscale", "down"]
-        } else {
-            toggleProcess.command = ["tailscale", "up"]
-        }
         toggleProcess.running = true
     }
 
@@ -141,7 +129,12 @@ PluginComponent {
             ToastService.showError("tailscalectl", "No clipboard tool found")
             return
         }
-        copyProcess.command = ["sh", "-c", "printf '%s' '" + text.replace(/'/g, "'\\''") + "' | " + root.clipboardCmd]
+        var cmd = TailscaleLib.buildCopyCommand(text, root.clipboardCmd)
+        if (!cmd) {
+            ToastService.showError("tailscalectl", "Invalid clipboard command")
+            return
+        }
+        copyProcess.command = cmd
         copyProcess.running = true
         ToastService.showInfo("Copied " + text + " to clipboard")
     }