release(v1.7.30-alpha): live install/uninstall progress + cleaner pull waterfall

- Backend: unified pull-progress streaming across primary AND fallback
  registries. Earlier code only streamed for the primary attempt; if it
  failed fast (VPS 404, etc.) the UI froze at 0% until the fallback
  finished. The waterfall now uses a single shared helper that streams
  podman stderr through update_install_progress for every URL tried.
- Backend: PackageDataEntry gains uninstall_stage, set at each phase of
  handle_package_uninstall ("Stopping containers (i/total)",
  "Cleaning up volumes", "Removing app data"). State flips to Removing
  during the pipeline.
- Frontend: MarketplaceAppCard renders the live progress bar with byte
  counts during installs, matching the System Update download bar style.
- Frontend: AppCard renders the live uninstall stage label per app.
  Modal closes immediately on confirm so concurrent uninstalls each
  show their own progress on their own card.
- Cleanup: removed dead helpers (image_candidates, rewrite_for_primary,
  primary_image_url, pull_from_registries_with_skip) made unused by
  the install.rs refactor.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

core/Cargo.lock

@@ -80,7 +80,7 @@ checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
 
 [[package]]
 name = "archipelago"
-version = "1.7.29-alpha"
+version = "1.7.30-alpha"
 dependencies = [
  "anyhow",
  "archipelago-container",