feat: Agent Office — AI 에이전트 가상 오피스 (#2)

## Summary
- Canvas 2D 픽셀아트 오피스 렌더링 (SpriteSheet + TileMap + AgentSprite)
- WebSocket 실시간 에이전트 상태 동기화 (useAgentManager)
- ChatPanel (명령/승인) + TaskHistory (작업 이력) UI
- 다크 테마 + glassmorphism 패널

## Changes (7 commits)
- API helpers + route + Lab entry
- Canvas engine: SpriteSheet, TileMap, AgentSprite, OfficeRenderer
- React hooks: useAgentManager, useOfficeCanvas
- Components: ChatPanel, TaskHistory
- Main page + CSS
- Code review fixes: claude agent 참조 제거, rejected 배지 추가

Reviewed-on: #2

src/api.js

@@ -588,3 +588,14 @@ export function deleteBrandLink(id) {
   return apiDelete(`/api/blog-marketing/links/${id}`);
 }
 
+// ── Agent Office ──────────────────────────────────
+export const getAgents         = ()           => apiGet('/api/agent-office/agents');
+export const getAgentDetail    = (id)         => apiGet(`/api/agent-office/agents/${id}`);
+export const updateAgentConfig = (id, body)   => apiPut(`/api/agent-office/agents/${id}`, body);
+export const getAgentTasks     = (id, limit=20) => apiGet(`/api/agent-office/agents/${id}/tasks?limit=${limit}`);
+export const getAgentLogs      = (id, limit=50) => apiGet(`/api/agent-office/agents/${id}/logs?limit=${limit}`);
+export const getPendingTasks   = ()           => apiGet('/api/agent-office/tasks/pending');
+export const sendAgentCommand  = (agent, action, params={}) => apiPost('/api/agent-office/command', { agent, action, params });
+export const approveAgentTask  = (agent, task_id, approved, feedback='') => apiPost('/api/agent-office/approve', { agent, task_id, approved, feedback });
+export const getAgentStates    = ()           => apiGet('/api/agent-office/states');
+