MAC-based IPv6 client identification without DHCP dependency

### Prerequisites

- [x] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) and found no answer

- [x] I have searched other issues and found no duplicates

- [x] I want to report a bug and not [ask a question or ask for help](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a)

- [x] I have set up AdGuard Home correctly and [configured clients to use it](https://github.com/AdguardTeam/AdGuardHome/wiki/Clients). (Use the [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) for help with installing and configuring clients.)

### Platform (OS and CPU architecture)

FreeBSD, ARM64

### Installation

GitHub releases or script from README

### Setup

On a router, DHCP is handled by the router

### AdGuard Home version

v0.107.57

### Action

Added client ipv6 suffix as client identifier (`::[fixed_part]`)

## Proposed Solution
Implement either:
- Pattern matching for client suffixes (`::[fixed_part]`)
- MAC-based IPv6 client identification without DHCP dependency

### Expected result

Persistent client identification through suffix wildcards or MAC binding

### Actual result

Requires full IPv6 address updates daily due to ISP prefix rotation

### Additional information and/or screenshots

_No response_