chore: change temp directory path of serve-release.sh

[yomybaby]

Improve WebUI Release Serving Script

This PR reorganizes the WebUI release download and serving process:

1. Creates a dedicated scripts/temp-releases/ directory for all downloaded WebUI releases
2. Updates .gitignore to reflect the new directory structure
3. Improves the serve-release.sh script with:
   • Better path handling using script directory detection
   • Automatic cleanup of downloaded zip files
   • Proper copying of config.toml from project root
   • Adds copying of plugins directory to the extracted WebUI

[yomybaby]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
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• chore: change temp directory path of serve-release.sh #4455 👈 (View in Graphite)
• feat(FR-1572): improve keyboard interaction and focus management for editable name components #4421
• main

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