Per repo policy, ~/.hermes/.env is for secrets only. Guild IDs are
behavioral configuration, not secrets. Replacing the
DISCORD_DM_ROLE_AUTH_GUILD env var from the original fix with
discord.dm_role_auth_guild in config.yaml.
- New module-level _read_dm_role_auth_guild() helper reads
hermes_cli.config.read_raw_config()['discord']['dm_role_auth_guild'].
Fails closed on any parse error (safe default = DM role-auth off).
- DEFAULT_CONFIG['discord'] gains dm_role_auth_guild: '' with a comment
documenting the opt-in.
- Tests patch hermes_cli.config.read_raw_config directly (via the
_set_dm_role_auth_guild helper) instead of setenv/delenv. 12 tests
in test_discord_roles_dm_scope pass; no env var involvement.
- Docstring + module docstring + comments updated to reference
discord.dm_role_auth_guild.
- E2E verified with real imports across 6 scenarios: unset, int,
string, garbage, zero, and (crucially) env-var-only-no-config all
return None except the valid int/string cases. Env var has zero
effect — policy compliance confirmed.