Announce that a load finished even when it failed

[Gabriel Dufresne (GabrielDuf)]

When ReloadPackages threw, the catch logged the exception and set IsLoading to false, but never raised FinishedLoading. The packages pages read "LoadsOnStart && !IsLoaded" as still-pending, so the page kept the "Loading packages" illustration forever -- and unlike the race fixed in #5387, navigating away and back re-ran FilterPackages against the same flags, so nothing short of hitting Reload cleared it.

Raise the event from the catch too, and have the pages ask HasPendingInitialLoad instead: a load that threw has concluded, even though it produced nothing. IsLoaded stays false on that path, so the callers that read it as "this list was never loaded, go fetch it" -- the IPC package list, the automatic updates editor, the maintenance scheduler's backup -- keep retrying exactly as they did before.

A FinishedLoading subscriber that throws unwinds into that same catch, so the announcement is guarded by a flag: a successful load whose subscriber threw must not fire the event a second time and re-run every handler that already ran, nor undo the state the success path just set. The announcement made from the catch is itself wrapped, so ReloadPackages still swallows what it swallowed before.

DiscoverablePackagesLoader re-arms its queued search from FinishedLoading, so a thrown load no longer strands that either.

[Copilot]

Copilot review overview

🟡 Changes recommended

A throwing completion subscriber can incorrectly mark a successful load—or a newly started reload—as failed.

Review effort: Balanced
Findings: 1

Open (1)

• Subscriber exceptions falsely mark successful loads as failed · New

What changed in this PR

Updates package loaders and pages to treat failed loads as completed.

Changes:

• Announces completion when loading throws.
• Adds pending-initial-load state for UI rendering.
• Adds failure and subscriber-exception tests.

File	Description
PackageLoaderPipelineTests.cs	Tests failed loads and throwing subscribers.
AbstractPackageLoader.cs	Tracks pending loads and announces failures.
PackagesPageViewModel.cs	Stops displaying indefinite loading after failure.

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[Copilot]

Copilot review overview

🔵 Needs a closer look

Failure events can trigger success-only automation, while throwing subscribers can prevent later handlers from receiving completion.

Review effort: Balanced
Findings: None

Resolved since last review (1)

• Subscriber exceptions falsely mark successful loads as failed

Previously missed (1)

In code that hasn't changed since last review

Isolate FinishedLoading subscriber failures

src/​UniGetUI.PackageEngine.PackageLoader/​AbstractPackageLoader.cs:266

This flag avoids invoking the whole event twice, but a multicast event stops at the first throwing subscriber, so every later subscriber is skipped permanently. A handler registered before the page/sidebar handlers can therefore leave those consumers in their loading state even though this method swallows the exception. Invoke each FinishedLoading handler independently with per-handler exception isolation, and extend the test with a recorder registered after the throwing handler.

This issue also appears on line 284 of the same file.

[randy-but-a-ro]

🤖 Pull request was approved automatically: the AI review is complete and all its review threads are resolved. 🎉

Integration Details

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