fix(web): fix View in Timeline not working for stacked assets

[Snowknight26]

Description

As non-primary assets in a stack don't appear in the timeline, attempting to use the View in timeline feature from the navigation bar attempted to navigate you to an asset that wasn't there. Instead, View in timeline now takes you to the stack's primary asset, which should always be available in the timeline.

Fixes #14987

How Has This Been Tested?

• Navigated from a stack in Photos -> changed to secondary asset -> menu -> View in timeline
• Regression tested other places that use the asset viewer - map, album page, various pages with asset grid

Screenshots (if appropriate)

vmware_2025-03-19_18-55-46.mp4

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/)