fix(fileIcons api): preserve sizing and folder state on plugin refresh

[bajrangCoder]

No description provided.

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge; the previously reported storage-color issue is fixed and no new actionable defects were identified.

Summary

This PR makes late plugin icon refreshes preserve File Browser sizing and storage-color hooks while correctly retaining closed-folder state.

• Preserves the structural icon and user-added-storage classes when replacing resolved glyph classes.
• Updates File Browser styling so storage color remains applicable after the built-in folder class is replaced.
• Adds regression coverage for file sizing and closed storage-folder refresh behavior.
• Strengthens existing highlighting and SFTP migration tests by asserting expected warnings.

_{Reviews (2) · Last reviewed commit: "fix"}

[bajrangCoder]

@greptile