[Bug]: About, App Updates — updating a winget copy from About leaves winget on the old version, so SysManager offers its own update again and runs it on itself #2889

Problem

The README's install line is winget install laurentiu021.SysManager, a portable package, and About's startup check (on unless the user turns it off) sees a new GitHub release hours or days before winget-pkgs accepts it. So a winget-installed copy is usually offered Download and Install first. UpdateApplier then moves the new build over Environment.ProcessPath in place. Nothing in the update path knows the copy belongs to winget: no .cs file names the laurentiu021.SysManager package or the WinGet\Packages folder, so winget keeps recording the version it installed.

Once winget-pkgs has the release:

• winget upgrade reports SysManager as out of date, and WingetService.ParseUpgradeTable lists every row, SysManager's own included. App Updates shows "SysManager → " and the Dashboard's app-updates alert counts it, while About says it is up to date on the new version.
• Upgrade selected on that row, and the Dashboard's Update All Apps (winget upgrade --all), ask winget to replace the exe SysManager is running from.

The same happens with no in-app update at all: a winget copy that is one release behind lists itself in App Updates, and upgrading it there targets the running file.

Steps to reproduce

1. Install with winget install laurentiu021.SysManager and start it, while an older version is the newest in winget.
2. When a newer GitHub release appears, use About's Download and Install update.
3. After winget-pkgs accepts that release, open App Updates: SysManager is listed as needing the update it already has.

Expected behavior

One update channel per copy: SysManager never offers its own package in App Updates or the Dashboard, and a winget-managed copy is updated through winget, so the file and winget's record agree.

Proposed fix

• Keep SysManager's winget id in one constant next to UpdateService.Owner/Repo, and drop rows with that id in ParseUpgradeTable, since About owns self-update. Run Update All as per-id upgrades over the listed rows so it never targets the running exe.
• Detect a winget-managed copy (Environment.ProcessPath under %LOCALAPPDATA%\Microsoft\WinGet\Packages\laurentiu021.SysManager_*, or the per-machine WinGet\Packages folder) and, for it, either run winget upgrade --id laurentiu021.SysManager -e after the old process exits or replace Install with "Installed through winget, update it with winget".
• Tests: an upgrade table that contains SysManager's own row lists everything except that row, and a process path under WinGet\Packages takes the winget route.

Affected tab

About, App Updates, Dashboard.