Bug: Error pop-ups don't appear when loading non-existent files

[coderabbitai]

Description

When attempting to load a non-existent file, the application should display an error pop-up, but currently nothing is shown.

Reproduction Steps

1. Visit https://y-scope.github.io/yscope-log-viewer/?filePath=does_not_exist
2. Notice that no error pop-up appears, even though a 404 error should be displayed

Root Cause

In the AppController component, setPostPopUp() is called in a useEffect hook, but this happens after the file loading attempt. Any errors that occur during file loading won't show a UI pop-up because the pop-up function reference hasn't been updated in the contextStore yet.

Proposed Solution

Move the setPostPopUp() call before loading a file to ensure that error pop-ups can be displayed for any errors during the file loading process.

References

• Referenced in PR: refactor: Replace StateContextProvider with Zustand for state management (resolves #168, resolves #211). #224
• Comment: refactor: Replace StateContextProvider with Zustand for state management (resolves #168, resolves #211). #224 (comment)

cc @junhaoliao