Desktop: a channel named `inbox` is missing from the sidebar (collides with the built-in Inbox view)

**Describe the bug**

A channel named exactly `inbox` is not listed in the Desktop sidebar's Channels
section. Everything else about it is fine: the relay has the channel, the
account is its owner, messages keep arriving in it, and the **Android client on
the same account and relay lists it normally**. Desktop shows every other
channel of the community and omits exactly the one named `inbox`.

The likely cause is a collision with the built-in **Inbox** view that Desktop
pins above Channels, next to Agents.

Renaming the channel on the relay from `inbox` to something else made it appear
in the Desktop sidebar immediately, without restarting the client. That is what
makes me fairly confident the name is what triggers it.

**Steps to reproduce**

1. Create a private stream channel named exactly `inbox`.
2. Join it with an account that uses Buzz Desktop.
3. Open Desktop and look at the Channels section of the sidebar — the channel
is not listed.
4. Open the same account in the Android client — it is listed there.
5. Rename the channel to anything else — it shows up in Desktop right away.

**Expected behavior**

The channel is listed under Channels like any other. The built-in Inbox view
and a user channel that happens to be called `inbox` should be able to coexist.
Failing that, channel creation could reject or warn about names that collide
with built-in views, so the channel does not silently become unreachable in one
client while staying visible in another.

**Version and platform**

- Buzz version: appeared after a recent Desktop update; I have not bisected
which release introduced it. Latest release at the time of writing is
`desktop-v0.5.23`. Relay is self-hosted from `ghcr.io/block/buzz`.
- OS: Linux (GNOME) for Desktop; Android for the client that still lists the
channel.

**Logs / additional context**

Relay-side state was verified while the channel was invisible in Desktop, and
nothing was wrong there:

- the channel row had neither `archived_at` nor `deleted_at` set,
- the account's `channel_members` row had no `removed_at` and no `hidden_at`,
- kind `39000`/`39001`/`39002` discovery events for the channel existed and were
current,
- inbound messages from integrations kept landing in the channel the whole time,
and other clients rendered them.

So this looks purely like Desktop sidebar rendering, not relay state or
membership.

Start by reproducing the issue in Buzz Desktop with a private channel named exactly `inbox`, then compare the Desktop sidebar's Channels section with the Android client. Trace the Desktop sidebar rendering and built-in Inbox view handling; done means the user channel appears under Channels while the built-in Inbox view remains available.

Written by the indexing model from the issue text.