feat(web): add last asset upload date to user admin details

[aviv926]

Description

This PR allows the system administrator to know when an asset was last uploaded by the user.
This helps in situations where the operating system or an unknown problem causes the backup to stop.
By adding this, the system administrator can see if a user has not uploaded an asset for a long time and try to help them resolve the problem.

How Has This Been Tested?

Experiment A:
Uploading an asset
Result:
Last uploaded today

Experiment B:
Delete the asset I uploaded
Result:
Last uploaded 2 days ago

Screenshots (if appropriate)

Experiment A:

Experiment B:

Checklist:

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation if applicable
• I have no unrelated changes in the PR.
• I have confirmed that any new dependencies are strictly necessary.
• I have written tests for new code (if applicable)
• I have followed naming conventions/patterns in the surrounding code
• All code in src/services/ uses repositories implementations for database calls, filesystem operations, etc.
• All code in src/repositories/ is pretty basic/simple and does not have any immich specific logic (that belongs in src/services/)

Please describe to which degree, if any, an LLM was used in creating this pull request.

yes
for luxon $derived part and also for web/src/routes/admin/users/[id]/+page.ts
...

[aviv926]

Btw if we merge this, we'll need to change the title Storage Quota to Storage Info.

[aviv926]

We can also use this option which is even more accurate in terms of time (even to the minute level) and it also uses the local language for the hour and time.
Let me know what you think

Suggested change

	let lastUploadText = $derived(
	let lastUploadText = $derived(
	user.lastAssetUploadedAt
	? (DateTime.fromISO(user.lastAssetUploadedAt).toRelative({ locale: $locale }) ?? $t('unknown_time'))
	: $t('never_uploaded'),
	);