Update ENVIRONMENT and ITERATION documentation; add industry background and role research

- Enhanced `ENVIRONMENT.md` with a new section on platform positioning and industry context, detailing the project's role as a comprehensive wealth management institution.
- Updated the service roles table to include insights from the four-role industry research.
- Added new files for "平台与行业背景" and "四角色行业调研" to provide detailed context and operational insights for the project's agents.
- Revised `ITERATION.md` to reflect the addition of these new documents and their relevance to user requirements.

docs/memory/MEMORY.md

@@ -130,6 +130,8 @@ RBAC 联调账号：scripts/dev/rbac-seed-reference.md
 | `docs/memory/ENVIRONMENT.md` | As-Is 业务环境与 Core 模拟说明 |
 | `docs/memory/TODO.md` | 当前待办与已完成 |
 | `docs/需求拆解/` | 业务原文（场景、矩阵、合规） |
+| `docs/需求拆解/用户故事/平台与行业背景.md` | 平台定位 + 行业常态 + 基金类型 |
+| `docs/需求拆解/用户故事/四角色行业调研.md` | 四角色真实工作流程与行业规则 |
 | `docs/项目框架设计/` | 表结构、JWT 手册、Core 模拟、技术版本 |
 | `docs/业务记忆管理/` | Redis 短期 vs MySQL/Milvus/Neo4j 权威记忆 |