fix: avoid manager flicker during instance polling

[TBDevMaster]

Summary

This fixes the manager UI flicker reported when the instances page refreshes every 5 seconds.

The issue happens because the instances polling path sets isLoading: true on every fetchInstances() call. The manager page uses that flag to swap the whole list for skeleton cards, so each polling cycle causes a visible full-page flash.

What changed

• added a hasLoaded flag to the instances store
• keep the skeleton/loading state only for the first load
• allow subsequent polling refreshes to update data in the background without replacing the whole page UI

Why this fixes the flicker

Before:

• initial load -> isLoading = true
• each 5s polling refresh -> isLoading = true again
• instances page re-renders skeletons every cycle

After:

• initial load -> isLoading = true
• after first successful load -> hasLoaded = true
• polling refreshes no longer set full-page loading
• list updates in place without visible flashing

Notes

This repository currently includes the built manager bundle, so the change is applied in manager/dist/assets/index-LD46dRLh.js.

Closes #11.

[sourcery-ai]

Sorry @TBDevMaster, your pull request is larger than the review limit of 150000 diff characters

[TBDevMaster]

Sourcery skipped this PR because the repository stores the manager as a built/minified bundle, so a very small functional change in manager/dist/assets/index-LD46dRLh.js appears as a very large diff to automated reviewers.

The actual logic change is small:

Before:

• fetchInstances() set isLoading = true on every polling refresh

After:

• added hasLoaded
• full-page loading is only shown on the first load
• subsequent 5s polling refreshes update data without replacing the list with skeletons

In other words, the functional change is:

// before
t({ isLoading: true, error: null })

// after
t((state) => ({ isLoading: !state.hasLoaded, error: null }))and successful/failed fetches now also set:

hasLoaded: true
This fixes the flicker reported in #11 while keeping the initial loading state intact.