for more information, see https://pre-commit.ci

… IPv6 tests (#55)

`_parse_hostport()` had manual bracket-parsing logic with no tests,
silently mishandled unbracketed IPv6 literals, and returned a plain
`str` host regardless of whether the value was a numeric IP address.

## Changes

- **`voip/__main__.py`**:
- Replaced manual bracket/partition logic with a single
`HOSTPORT_PATTERN` regex that handles `[IPv6HOST][:PORT]`, `HOST:PORT`,
and bare `HOST` forms.
- Return type changed from `tuple[str, int]` to `tuple[IPv4Address |
IPv6Address | str, int]` — numeric IP literals are parsed into typed
address objects; hostnames remain `str`.
- Unbracketed IPv6 literals (e.g. `::1`) raise `click.BadParameter`
directing the user to bracket notation.
- `_parse_stun_server` converts the typed host to `str` for
socket/asyncio compatibility.
- `_connect_sip` uses `str(proxy_addr[0])` when calling
`asyncio.create_connection`.
- **`voip/sip/protocol.py`**: `outbound_proxy` type updated to
`tuple[IPv4Address | IPv6Address | str, int] | None`.
- **`tests/test_main.py`**: New `TestParseHostport` class covering the
three key paths:
  - `[::1]` → `(IPv6Address("::1"), 5061)` (default port)
  - `[::1]:5061` → `(IPv6Address("::1"), 5061)` (explicit port)
  - `::1` → `BadParameter("...enclosed in brackets...")`

```python
# Before: silently wrong, plain str host
_parse_hostport(None, None, "::1")   # → ("::", 1)
_parse_hostport(None, None, "[::1]") # → ("::1", 5061)

# After: explicit error for unbracketed IPv6, typed address objects
_parse_hostport(None, None, "::1")
# click.BadParameter: IPv6 address must be enclosed in brackets, e.g. [::1].
_parse_hostport(None, None, "[::1]")  # → (IPv6Address('::1'), 5061)
_parse_hostport(None, None, "1.2.3.4:5060")  # → (IPv4Address('1.2.3.4'), 5060)
```

<!-- START COPILOT CODING AGENT TIPS -->
---

📍 Connect Copilot coding agent with [Jira](https://gh.io/cca-jira-docs),
[Azure Boards](https://gh.io/cca-azure-boards-docs) or
[Linear](https://gh.io/cca-linear-docs) to delegate work to Copilot in
one click without leaving your project management tool.

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: codingjoe <[email protected]>
Co-authored-by: Johannes Maron <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>