Frontend de-Pi (Stage 3). Renames the chat hook usePiChat → useChat (+ UsePiChatType → UseChatType, file moved to hooks/useChat.ts) across all consumers, and renames the TaskRunnerModal agentic runner PiMonoInner → AgenticTaskRunner (dropping the dead defaultProvider === 'pi' check → always the Claude default). Pure rename, no behavior change. The WS route stays /api/pi/chat/ws until Stage 4. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>