feat(data): stream sim episodes with raw ee actions

docs/superpowers/plans/2026-03-30-streaming-hdf5-ee-action.md

@@ -0,0 +1,42 @@
+# Streaming HDF5 EE Action Dataset Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** 将 Diana 仿真采集改为流式写入 HDF5，图像保存为 256x256 的四路相机视角，并把 `/action` 改为 IK 前的原始末端位姿动作。
+
+**Architecture:** 新增一个独立的流式 HDF5 episode writer，负责逐帧写入 qpos、原始 action 和 resize 后图像，并在 episode 成功时原子提交、失败时删除临时文件。采集脚本只负责 rollout 和把每一步观测/动作交给 writer，避免整集数据先堆在内存里。
+
+**Tech Stack:** Python, h5py, numpy, cv2, unittest, MuJoCo demo scripts
+
+---
+
+### Task 1: 为流式 writer 建立测试边界
+
+**Files:**
+- Create: `tests/test_streaming_episode_writer.py`
+- Create: `roboimi/utils/streaming_episode_writer.py`
+
+- [ ] **Step 1: Write the failing test**
+- [ ] **Step 2: Run `python -m unittest tests.test_streaming_episode_writer -v` and confirm it fails because the writer module does not exist**
+- [ ] **Step 3: Implement the minimal streaming writer with temp-file commit/discard, per-frame append, and 256x256 image resize**
+- [ ] **Step 4: Re-run `python -m unittest tests.test_streaming_episode_writer -v` and confirm it passes**
+
+### Task 2: 接入 Diana 采集脚本
+
+**Files:**
+- Modify: `roboimi/demos/diana_record_sim_episodes.py`
+- Reuse: `roboimi/utils/streaming_episode_writer.py`
+
+- [ ] **Step 1: Replace in-memory `data_dict` / `obs` accumulation with per-episode streaming writer lifecycle**
+- [ ] **Step 2: Keep four cameras (`angle`, `r_vis`, `top`, `front`) and resize to 256x256 before persistence**
+- [ ] **Step 3: Capture raw policy output before IK and write that to `/action`**
+- [ ] **Step 4: On success commit to `episode_{idx}.hdf5`; on failure remove temp file**
+
+### Task 3: 验证改动
+
+**Files:**
+- Verify only
+
+- [ ] **Step 1: Run unit tests for the writer**
+- [ ] **Step 2: Run one end-to-end collection episode and stop after `episode_0.hdf5` becomes readable**
+- [ ] **Step 3: Verify HDF5 keys and shapes: `action=(700,16)`, image datasets are `(700,256,256,3)`, and `/action` matches raw EE action semantics**