feat: add progress indicator to app list during updates

[Medformatik]

Show download and install progress for each app in the updates tab when using "Update all". Extracts DownloadStatus to a shared sealed interface used by both AppListAdapter and AppDetailAdapter.

Related issues:

• Update progress #341
• "Update all"-button should show some indication that it has been pressed #1156

[Iamlooker]

Can you also share a screenshot, or a screen recording of this. It would be helpful

[Iamlooker]

Thanks a lot for the PR btw

[Medformatik]

screen-20260117-092309-1768638159531.mp4

[Iamlooker]

I will be pointing this to a new branch so I can do some UI changes

Awesome work man

[Iamlooker]

In my testing this does not feel stable. I encountered following issues:

• Install status is not shown on initial load
• After installation the whole app item disappears sometime (even from Explore page)
• Does not properly show the Installing state

[Medformatik]

Sorry for not noticing those problems. I'll take another look at it.

[Medformatik]

I've investigated and fixed all three issues:

1. Install status not shown on initial load
   The sample(200) on the download state flow was delaying the first emission. Now we process the initial state immediately when the service binds, then sample subsequent updates.

2. App items disappearing
   This was caused by a race condition between download and install states. When a download completes, it sets Idle status. But due to sampling, this could arrive after the install state had already set PendingInstall, overwriting it and causing a visual glitch.
   Fixed by separating download and install status tracking in the adapter, with install status taking priority. This ensures the Installing indicator stays visible even if a delayed download Idle update arrives.

3. Installing state not shown properly
   InstallState.Pending was incorrectly mapped to DownloadStatus.Pending (waiting to download) instead of DownloadStatus.PendingInstall (waiting to install). This meant the UI showed the wrong indicator after download completed.

Additionally, I added tracking for active packages to properly clean up stale statuses when packages are removed from the queue without going through normal completion.

I have opened up a follow-up PR for this #1178.