Promotes the AI assistant out of Settings into a first-class "AI Agents"
sidebar area.
- Sidebar: new "AI Agents" item → /agents.
- /agents page with two tabs:
- Playground — a test chat (POST /api/ai/playground) that runs the
real auto-reply path (KB retrieval + provider, auto_reply prompt,
multi-turn, shows handoff). loadAiConfig gains requireActive so you
can test before enabling.
- Setup — the existing provider/key + knowledge-base config, relocated.
- Removed the AI section from Settings (settings-sections + page); same
account config, new home. No migration.
Tests +6 (query, loadAiConfig requireActive). 593 pass; typecheck, lint,
build green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>