docs(i1): engineering index, parallel tracks, and product context

Add PARALLEL_ITERATION_INDEX, workspace layout, system architecture,
three-track execution packs, BPM/product references, and planned
service manifests. Supports I1 alignment across backend, web, and SDK.

Made-with: Cursor

engineering/README.md

@@ -0,0 +1,19 @@
+# 工程元数据（Engineering）
+
+本目录存放 **工作区边界说明** 与 **规划中的独立工程占位**，不引入额外构建步骤。
+
+
+| 文件/路径                                                | 说明                                                                                                           |
+| ---------------------------------------------------- | ------------------------------------------------------------------------------------------------------------ |
+| `[workspace-manifest.json](workspace-manifest.json)` | 机器可读：当前组件路径、建议独立仓库列表                                                                                         |
+| `[planned/](planned/)`                               | 规划工程 README 占位（Webhook、平台 API、平台 UI）                                                                         |
+| **系统架构全景（C4、时序、全量组件表、§9 安全架构）**               | `[../docs/engineering/SYSTEM_ARCHITECTURE.md](../docs/engineering/SYSTEM_ARCHITECTURE.md)` |
+| **OpenAPI 契约（SSOT）**                                  | `[../contracts/README.md](../contracts/README.md)` · `openapi/delivery-platform-api.json` |
+| **平台部署 Runbook**                                     | `[../services/RUNBOOK.md](../services/RUNBOOK.md)` |
+| 详细架构走查                                               | `[../docs/engineering/WORKSPACE_ENGINEERING_LAYOUT.md](../docs/engineering/WORKSPACE_ENGINEERING_LAYOUT.md)` |
+| 三轨并行迭代（后端 / 前端 / SDK）                              | `[../docs/engineering/PARALLEL_ITERATION_INDEX.md](../docs/engineering/PARALLEL_ITERATION_INDEX.md)` · `[../docs/engineering/tracks/](../docs/engineering/tracks/)` |
+
+
+**原则**：**授权 SDK**（`java/`、`native/`）与 **商业交付平台**（Spring + Vue）**分仓或分流水线**，避免服务端依赖 JNI/native 与客户端库混用。
+
+**部署形态**：平台/Webhook 后端采用 **多模块开发 + 单 Fat JAR**（仅 bootstrap 模块 `repackage`）；SDK 侧为 **多枚 library jar + native**，**不打** Spring Boot 可执行包 —— 详见 [WORKSPACE_ENGINEERING_LAYOUT.md §5](../docs/engineering/WORKSPACE_ENGINEERING_LAYOUT.md)。