Fix uninstall button error (#1306)

## Motivation

Fix "Network setup script failed" error when clicking uninstall button
and resolve Xcode compiler warnings.

## Changes

- NetworkSetupHelper.swift: Add || true guards and explicit return 0 in
find_and_enable_thunderbolt_bridge to prevent script failures with set
-euo pipefail
- ThunderboltBridgeService.swift: Use withCString and
withUnsafeMutablePointer for Authorization API calls to fix pointer
lifetime warnings
- EXOApp.swift: Mark showNotification as nonisolated to fix main actor
isolation warning

## Why It Works

- The uninstall script's Thunderbolt re-enable function could exit
non-zero in edge cases (no bridges, no matches). Since this is a cleanup
step, failures should not abort uninstall.
- Swift requires explicit pointer lifetime management when passing
strings/structs to C APIs.
- showNotification is called from a nonisolated delegate method and uses
thread-safe APIs.

## Test Plan

### Manual Testing
Hardware: MacBook Pro

- Clicked Uninstall button, verified it completes without error
- Built in Xcode, verified no warnings   

### Automated Testing
N/A

app/EXO/EXO/EXOApp.swift

@@ -225,7 +225,7 @@ private final class ExoUpdaterDelegate: NSObject, SPUUpdaterDelegate {
         }
     }
 
-    private func showNotification(title: String, body: String) {
+    nonisolated private func showNotification(title: String, body: String) {
         let center = UNUserNotificationCenter.current()
         let content = UNMutableNotificationContent()
         content.title = title

app/EXO/EXO/Services/NetworkSetupHelper.swift

@@ -241,11 +241,11 @@ enum NetworkSetupHelper {
         rm -f "$LOG_OUT" "$LOG_ERR"
 
         # Switch back to Automatic network location
-        networksetup -switchtolocation Automatic 2>/dev/null || true
+        networksetup -switchtolocation Automatic >/dev/null 2>&1 || true
 
         # Delete the exo network location if it exists
-        networksetup -listlocations | grep -q '^exo$' && {
-          networksetup -deletelocation exo 2>/dev/null || true
+        networksetup -listlocations 2>/dev/null | grep -q '^exo$' && {
+          networksetup -deletelocation exo >/dev/null 2>&1 || true
         } || true
 
         # Re-enable any Thunderbolt Bridge service if it exists
@@ -255,12 +255,12 @@ enum NetworkSetupHelper {
           tb_devices=$(networksetup -listallhardwareports 2>/dev/null | awk '
             /^Hardware Port:/ { port = tolower(substr($0, 16)) }
             /^Device:/ { if (port ~ /thunderbolt/) print substr($0, 9) }
-          ')
+          ') || true
           [ -z "$tb_devices" ] && return 0
 
           # For each bridge device, check if it contains Thunderbolt interfaces
           for bridge in bridge0 bridge1 bridge2; do
-            members=$(ifconfig "$bridge" 2>/dev/null | awk '/member:/ {print $2}')
+            members=$(ifconfig "$bridge" 2>/dev/null | awk '/member:/ {print $2}') || true
             [ -z "$members" ] && continue
 
             for tb_dev in $tb_devices; do
@@ -269,7 +269,7 @@ enum NetworkSetupHelper {
                 service_name=$(networksetup -listnetworkserviceorder 2>/dev/null | awk -v dev="$bridge" '
                   /^\\([0-9*]/ { gsub(/^\\([0-9*]+\\) /, ""); svc = $0 }
                   /Device:/ && $0 ~ dev { print svc; exit }
-                ')
+                ') || true
                 if [ -n "$service_name" ]; then
                   networksetup -setnetworkserviceenabled "$service_name" on 2>/dev/null || true
                   return 0
@@ -277,8 +277,9 @@ enum NetworkSetupHelper {
               fi
             done
           done
+          return 0
         }
-        find_and_enable_thunderbolt_bridge
+        find_and_enable_thunderbolt_bridge || true
 
         echo "EXO network components removed successfully"
         """

app/EXO/EXO/Services/ThunderboltBridgeService.swift

@@ -127,21 +127,24 @@ final class ThunderboltBridgeService: ObservableObject {
 
         // 2. Request specific network configuration rights
         let rightName = "system.services.systemconfiguration.network"
-        var item = AuthorizationItem(
-            name: rightName,
-            valueLength: 0,
-            value: nil,
-            flags: 0
-        )
-        var rights = AuthorizationRights(count: 1, items: &item)
-
-        status = AuthorizationCopyRights(
-            authRef,
-            &rights,
-            nil,
-            [.extendRights, .interactionAllowed],
-            nil
-        )
+        status = rightName.withCString { nameCString in
+            var item = AuthorizationItem(
+                name: nameCString,
+                valueLength: 0,
+                value: nil,
+                flags: 0
+            )
+            return withUnsafeMutablePointer(to: &item) { itemPointer in
+                var rights = AuthorizationRights(count: 1, items: itemPointer)
+                return AuthorizationCopyRights(
+                    authRef,
+                    &rights,
+                    nil,
+                    [.extendRights, .interactionAllowed],
+                    nil
+                )
+            }
+        }
         guard status == errAuthorizationSuccess else {
             if status == errAuthorizationCanceled {
                 throw ThunderboltBridgeError.authorizationCanceled