fix(editor): preserve active files position after restart

[bajrangCoder]

No description provided.

[greptile-apps]

Greptile Summary

This PR centralizes application of the open-file-list layout state and applies the persisted tab position during editor construction, preserving the selected header, sidebar, or bottom placement after restart.

• Applies persisted layout attributes when the pane root is created.
• Keeps pane-tab visibility, tab position, and the root layout attribute synchronized.
• Removes duplicate layout mutations from the individual rendering branches.

Confidence Score: 5/5

The PR appears safe to merge, with no concrete changed-code failure identified.

Persisted settings are initialized before editor construction, the new layout helper safely updates detached pane elements, and synchronization consistently reads the committed layout value.

Important Files Changed

Filename	Overview
src/lib/editorManager.js	Centralizes open-file-list layout DOM state and restores it during initialization; no actionable regression was identified.

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