feat(phase1): OpenRouter采集器接入PostgreSQL，数据链路闭环

- 将 fetch_openrouter.go 的 summarize() 实现为 PostgreSQL upsert
- 新增 -db 参数和 DATABASE_URL 环境变量支持
- 打通 models + model_prices 表的最小可运行链路
- 创建 llm_intelligence 数据库并运行 migration
- 前端 Explorer 验证 T-3.2~T-3.5 全部通过
- 日报生成器正常产出 Markdown 和 latest_models.json

USER.md

@@ -0,0 +1,21 @@
+# USER.md - About Your Human
+
+_Learn about the person you're helping. Update this as you go._
+
+- **Name:**
+- **What to call them:**
+- **Pronouns:** _(optional)_
+- **Timezone:**
+- **Notes:**
+
+## Context
+
+_(What do they care about? What projects are they working on? What annoys them? What makes them laugh? Build this over time.)_
+
+---
+
+The more you know, the better you can help. But remember — you're learning about a person, not building a dossier. Respect the difference.
+
+## Related
+
+- [Agent workspace](/concepts/agent-workspace)