## Objective

Let projects and language-specific settings add scopes where edit
predictions are disabled without repeating inherited scopes.

Part of #64399.

## Solution

Extend the `"..."` convention from #62769, #64222, #64440, #64484, and
#64540 to `edit_predictions_disabled_in`. For example, a global
`["comment"]` and a language override of `["string", "..."]` disable
predictions in both scopes.

Inherited scopes are inserted at `"..."`, and duplicates keep their
first occurrence. Omitting the marker replaces the list, `[]` clears it,
and omitting the setting preserves inheritance. The default remains
`[]`.

## Testing

Tested on macOS through settings loading, covering project and
language-specific overrides, inheritance, replacement, and clearing. The
language settings tests passed. Live editor behavior has not been
checked manually.

To check manually, configure global `["comment"]` and a language
override of `["string", "..."]`. Confirm predictions are disabled in
both scopes, then remove `"..."` and repeat with `[]` to check
replacement and clearing.

## Self-Review Checklist:

- [x] I’ve reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content adheres to Zed’s UI standards
([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
and
[icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md)
guidelines)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

---

Release Notes:

- Added support for `"..."` in `edit_predictions_disabled_in` so project
and language-specific settings can extend inherited scopes.

---------

Co-authored-by: Kirill Bulatov <mail4score@gmail.com>