TASK 48 slice 3: the self-updater is deleted - the Store updates the app

The creator's ruling (2026-09-27) is Store MSIX + Store IAP, so Microsoft delivers
the updates and the in-app updater is gone rather than parked. This is a
COMPLIANCE action, not cleanup: the Velopack bootstrap downloaded and executed a
payload, which Store policy 10.2.2 does not permit.

Three edit sites, as planned: the PackageReference in ytLive.csproj, 'using
Velopack;' in App.xaml.cs, and the bootstrap block. The self-hosted DigitalOcean
update-URL droplet dies with it.

Guard: ytLive.Tests/StorePackagingTests.cs - the ONE test asserts the app project
references no updater package (Velopack/Squirrel/NetSparkle/AutoUpdater/WinSparkle)
and that no app source file uses the updater API. The check matches CODE (a using
directive, a type usage), not a bare word, so a file's prose may still name what it
deliberately does not do.

Smoke-tested after the removal: MainWindow loaded, 0 exceptions in startup.log.
Full suite 437/437, 0 warnings.

ai.md

@@ -2583,8 +2583,10 @@ before re-deriving it. Executable checklist: `TASKS/task-48-distribution-msix.md
 
 **Consequences that are architecture, not packaging detail:**
 
-- **⛔ Velopack and the update URL are deleted** — the Store auto-updates. 3 edit sites,
-  `ytLive.csproj:92` + `App.xaml.cs:3,38-46`. The self-hosted DO droplet dies with it.
+- **⛔ Velopack and the update URL are deleted** — the Store auto-updates. **DONE 2026-10-22**
+  (TASK 48 slice 3): the `PackageReference` in `ytLive.csproj` and the bootstrap in
+  `App.xaml.cs` are gone, and `ytLive.Tests/StorePackagingTests.cs` guards that no updater
+  package or updater API comes back. The self-hosted DO droplet dies with it.
 - **⛔ The Polar licensing subsystem is deleted** — `PolarLicenseService`, `PolarLicense`,
   `MainViewModel.License.cs` (`PremiumUrl`, customer portal, the
   `OfflineGracePeriod = 14 days` subscription-era artifact, renewal/lapse copy), and the