[Feature] Support App Links / Deep Linking for custom self-hosted domains on Android

[ldbl1]

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request.

• Yes

The feature

When using a self-hosted dashboard (like Homepage) installed as a PWA on Android, tapping the Immich link (https://my-custom-domain.com) opens a new Chrome tab instead of the native Immich Android app.
Since Android 12+, the OS requires App Links to be explicitly verified. Looking at the Android settings for the Immich app ("Supported web addresses"), only my.immich.app is registered. Because of this, Android completely prevents users from manually adding their own self-hosted domains to the supported links list, trapping the user in the browser.

Describe the solution you'd like
I would like the ability to deep-link into the native Android app using my custom domain.
Since Immich is a self-hosted platform and you cannot pre-verify every user's custom domain with assetlinks.json, it would be great if the app's AndroidManifest.xml could include a generic intent filter for https schemes without the autoVerify="true" tag, or explicitly support a custom URI scheme (e.g., immich://my-custom-domain.com). This would at least allow Android users to manually go into Settings > Apps > Immich > "Open by default" and manually add their domain to the allowed list.

Describe alternatives you've considered
Currently, the only workaround is changing the dashboard link to use a direct Android Intent URI:
intent://my-custom-domain.com/#Intent;scheme=https;package=app.alextran.immich;end;
While this forces the app to open and bypasses Chrome, it is a hacky solution that breaks the link if the dashboard is accessed from a desktop browser or an iOS device.

Additional context

Platform

• Server
• Web
• Mobile

[bo0tzz]

#22184