UX Improvement for Selecting Existing Linked Account Owner IDs

### Required Pre-requisites

- [x] I have read the [Documentation](https://www.aci.dev/docs)
- [x] I have searched the [Issue Tracker](https://github.com/aipotheosis-labs/aci/issues) and [Discussions](https://github.com/aipotheosis-labs/aci/discussions) that this hasn't been reported yet.
- [x] Consider asking in [Discussions](https://github.com/aipotheosis-labs/aci/discussions) first

### Motivation

Motivation:

Currently, when configuring a linked account and associating it with an existing Linked Account Owner ID, users are required to manually input the identifier.

This manual input process presents two challenges:

- Users must remember or locate the exact identifier they previously created.
- As the number of Linked Account Owner IDs grows, management becomes increasingly complex and error-prone (e.g., typos, misidentification).


### Proposed Solution

Proposed solution:

Introduce a dropdown selection UI that:

- Displays all existing Linked Account Owner IDs.
- Allows users to select an ID from a list instead of typing.