fix(#390): Add admin elevation check to fail fast with clear error me…

[Randomlyclueless]

Closes #390

Proposed Changes

• Added src/Infrastructure/Helpers/AdminGuard.cs — a static guard class that checks for Windows administrator privileges using WindowsPrincipal/WindowsIdentity, following the same pattern as the existing RegistryGuard.cs
• Modified src/Infrastructure/AppRunner.cs to call AdminGuard.EnsureAdministrator() at the start of RunAsync(), before any config loading or system operations
• Added tests/WinHome.Tests/AdminGuardTests.cs with 3 unit tests covering admin, non-admin, and reset delegate scenarios

Type of Change

• 🐛 Bug fix
• 🧪 Testing

Screenshots / Logs (if applicable)

Non-admin shell (before fix would silently fail, now shows clear error):

Admin shell (runs normally with full execution):

Testing & Verification

• I have run dotnet test and all 60+ cross-platform tests passed (537 total: 536 succeeded, 1 skipped).
• I have verified the changes on a Windows environment (if applicable).
• I have added new unit tests to cover my changes.

GSSOC 2026 Checklist

• I have read the Contribution Guidelines.
• My code is formatted correctly (I have run dotnet format, uv tool run ruff format plugins/, and bun x prettier --write plugins/).
• I have linked the PR to an approved issue.
• I understand that a maintainer must apply the gssoc:approved label for this PR to count for points.

[DotDev262]

Compilation error: duplicate using statement

In src/Infrastructure/AppRunner.cs, there is a duplicate using directive at the top of the file:

The using WinHome.Interfaces; appears twice (before and after the new line). This will prevent the code from compiling. Please remove the duplicate and re-push.

Once this is fixed and the build passes, the PR should be good to merge!

[DotDev262]

Compilation error: duplicate using statement

In src/Infrastructure/AppRunner.cs, there is a duplicate using directive at the top of the file:

Lines 1 and 3 both have using WinHome.Interfaces; — this won't compile. Please remove the duplicate.

Once this is fixed and the build passes, the PR should be good to merge!

[DotDev262]

Compilation error: duplicate using statement

In src/Infrastructure/AppRunner.cs, using WinHome.Interfaces; appears twice:

using WinHome.Interfaces;  // line 1 — KEEP
using WinHome.Models;
using WinHome.Services.Logging;
using YamlDotNet.Serialization;
using YamlDotNet.Serialization.NamingConventions;
using WinHome.Infrastructure.Helpers;  // NEW line
using WinHome.Interfaces;              // line 7 — REMOVE THIS (duplicate)

Remove the duplicate using WinHome.Interfaces; on line 7, keep everything else. Once fixed and build passes, this is ready to merge.