fix(web): stop intercepting original assets in service worker

[CatMe0w]

Description

Default video playback uses the /video/playback endpoint, which already bypasses the service worker and allows the browser to use native byte-range requests.

Enabling "Play original video" switches playback to the /original endpoint. This endpoint is currently intercepted and deduplicated by the service worker, causing affected original videos to be downloaded in full before playback. This is inconsistent with the existing default /video/playback playback behavior and should not be an expected approach of playing the original file.

Limit service worker handling to thumbnail requests, matching its documented scope.

How Has This Been Tested?

• Confirmed original video requests bypass the service worker and receive 206 Partial Content responses.
• Confirmed thumbnails, hovering video previews and original images continue to load normally.

Screenshots (if appropriate)

Checklist:

• I have carefully read CONTRIBUTING.md
• 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.

An LLM was used to help set up a local dev environment. This change was manually written and tested.

[immich-push-o-matic]

Label error. Requires exactly 1 of: changelog:.*. Found: 🖥️web. A maintainer will add the required label.

[mertalev]

The original there is probably in reference to viewing the original image rather than videos.