Two follow-ups to the cherry-picked PR #9873 (`e3bcc819`):
1. `_is_allowed_user` now uses `getattr(self, '_allowed_*_ids', set())`
so test fixtures that build the adapter via `object.__new__`
(skipping __init__) don't crash with AttributeError.
See AGENTS.md pitfall #17 — same pattern as gateway.run.
2. New 3-case regression coverage in test_discord_bot_auth_bypass.py:
- role-only config bypasses the gateway 'no allowlists' branch
- roles + users combined still authorizes user-allowlist matches
- the role bypass does NOT leak to other platforms (Telegram, etc.)
3. Autouse fixture in test_discord_bot_auth_bypass.py clears all Discord
auth env vars before each test so DISCORD_ALLOWED_ROLES leakage from
a previous test in the session can't flip later 'should-reject' tests
into false-pass.
Required because the bare cherry-pick of #9873 only added the adapter-
level role check — it didn't cover the gateway-level _is_user_authorized,
which still rejected role-only setups via the 'no allowlists configured'
branch.
e5b880264b