feat: migrate user settings and agent management to gettext
Migrates all remaining user settings and agent management flash messages to gettext:
User Settings:
- session_manager.ex: mobile device removal, alert preferences, browser session revocation, revoke all sessions
- totp_manager.ex: device creation, verification, deletion, recovery code generation
- api_token_manager.ex: token creation, deletion, validation errors
- user_auth.ex: policy consent acceptance message
Agent Management:
- agent_live/edit.ex: agent update success
- agent_live/index.ex: agent/cloud poller creation, token regeneration, agent deletion, global default settings
All flash messages now use domain-specific helpers (t_auth, t_equipment) for proper internationalization.
Tests passing: 4165 tests, 0 failures
Graham McIntire
9a60bfec58