No longer works with cursor

**Describe the bug**
Cursor agents now require a provider:

**Steps to reproduce**
Simply updated the app after a week of running without issue

**Expected behavior**
Continue working with cursor

**Version and platform**
v0.5.5
OS: Linux - cachyos

**Logs / additional context**
=== starting Fizz (424241de7c5142a56a0cc559d166206e6a9dd10159abdf2d11ecdbaaf537f3ab) at 2026-08-06T11:14:28.712053973+00:00 ===
2026-08-06T11:14:28.713126Z INFO buzz_acp: buzz-acp: setup payload present, entering setup-listener mode
2026-08-06T11:14:28.713138Z INFO buzz_acp::setup_mode: buzz-acp entering setup mode agent=Fizz requirements=1
2026-08-06T11:14:28.718838Z INFO buzz_acp::setup_mode: setup-mode: connected and subscribed to membership notifications
2026-08-06T11:14:28.718896Z INFO buzz_acp: owner resolved from BUZZ_AUTH_TAG: 79f28cd681a1f6a31fb74946eac64ac610d7ae44894d51352ffbeed469f5afcb
2026-08-06T11:14:28.725348Z INFO buzz_acp::setup_mode: setup-mode: discovered 4 channel(s)
2026-08-06T11:14:28.725364Z INFO buzz_acp::setup_mode: setup-mode: subscribed to channel fd27333f-7731-4300-9403-a27a87c32c58
2026-08-06T11:14:28.725370Z INFO buzz_acp::setup_mode: setup-mode: subscribed to channel b18ce942-123d-4ac3-998f-d192edb82b98
2026-08-06T11:14:28.725372Z INFO buzz_acp::setup_mode: setup-mode: subscribed to channel 2138a91d-8c2e-4756-afb1-455490cd4852
2026-08-06T11:14:28.725373Z INFO buzz_acp::setup_mode: setup-mode: subscribed to channel 3da488e4-1775-4059-96c6-e62c026b60ce
2026-08-06T11:14:37.614330Z INFO buzz_acp::setup_mode: setup-mode: nudge published channel_id=b18ce942-123d-4ac3-998f-d192edb82b98 event_id=e578059f1c88ab92115ac780dde768305818ac8e2586f928655c1fb60f1011dd

Start by reproducing the Cursor failure on Linux with v0.5.5 and trace the buzz_acp::setup_mode startup path shown in the logs, focusing on where the provider requirement is handled. The issue names no source file or test, so locate the relevant Cursor/agent setup entry point first. Done means the app connects and continues working with Cursor without requiring an unsupported or missing provider.

Written by the indexing model from the issue text.