Autofill not working in discord app

### Checks

- [x] I have read the Wiki, searched the open issues, and still think this is a new bug.

### Explain the problem clearly and succinctly:

After following the steps in #2256 as well as thw wiki page for autofill I got autofill working in firefox. It remains defunct in apps (doesn't work at all in discord, works only for password field and does not fill username). Possibly other apps, I use very few login-gated apps.

Discord:

Expected:

Discord's help popup is unhelpful

No such setting exists

### Describe what you expected to happen:

I expected autofill to show and to populate both username and password.

### KeePassDX version:

4.3.2

### Build:

Libre

### Database version:

V2 - KDBX4.1

### File provider (`content://` URI)

_No response_

### Android version:

16 (kernel 6.1.145 | build number BP4A.251205.006)

### Android device:

Google Pixel 6 Pro

### Additional context:

Heliboard 3.6

Start by reproducing the issue in Discord on Android 16 with KeePassDX 4.3.2, comparing the reported Firefox behavior with app autofill. Trace the autofill entry point and its handling of Discord fields; done means the autofill UI appears and populates both username and password.

Written by the indexing model from the issue text.