Add favorites tab to library Modal [SYNTH-269]

[RoushilS]

Task

SYNTH-269

Symptom

Users would have to click through years in the library assembly multiple times, which can be annoying.

Solution

Add new tab with frontent favorite display logic, as well as backend default loading of selected assets. Also briefely updated tutorial.

Verification

• Users can favorite and unfavorite assets
• Best assets are favorited by default.
• Existing functionality preserved

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Before merging, ensure the following criteria are met:

• All acceptance criteria outlined in the ticket are met.
• Necessary test cases have been added and updated.
• A feature toggle or safe disable path has been added (if applicable).
• User-facing polish:
  • Ask: "Is this ready-looking?"
• Cross-linking between Jira and GitHub:
  • PR links to the relevant Jira issue.
  • Jira ticket has a comment referencing this PR.

[rutmanz]

Are the year tabs supposed to be gone?

Also I think it might be better to have the favorites tab always present (either as "Favorites" or with the star icon) and just show "No favorited assets yet!" if empty.

Also it looks like the defaults don't work quite right, when I opened it, nothing from the assetpack was favorited.

Also maybe auto-favorite local uploads because they'll probably be likely to use the models they add themselves

[Dhruv-0-Arora]

@rutmanz you have to clear storage if the thumbnails + years are not showing up