### Summary
This adds missing document lifecycle examples for the SDK and HTTP API.
Chat, retrieval, and chunk examples were already covered and unchanged.
Fix SDK examples polling status "1" which the API never returns — it returns mapped names like "DONE". Both loops timed out even on success. Now checks "DONE". The SDK already does this correctly. Failed parsing still times out (pre-existing).
Closes#4310
### What problem does this PR solve?
Issue #4310 requests practical examples for the RAGFlow SDK and HTTP API
to help developers get started faster. The existing `example/sdk/`
folder only contains `dataset_example.py`. This PR fills the remaining
gaps by adding examples for three key API areas not yet covered in
`main` or by other open PRs (#13904, #13284):
- **Chunk management** — add, list, update, delete, and retrieve chunks
within a dataset
- **Chat assistant** — create a chat assistant, open a session, send
messages (streaming and non-streaming), and clean up
- **Retrieval** — perform semantic retrieval across one or multiple
datasets
### Type of change
- [x] Documentation Update
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
Support getting aggregated parsing status to dataset via the API
Issue: #12810
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
Co-authored-by: heyang.why <heyang.why@alibaba-inc.com>
### What problem does this PR solve?
- typos
- IDE warnings
### Type of change
- [x] Refactoring
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
### Type of change
- [x] Refactoring
- [x] Performance Improvement
Signed-off-by: zhanluxianshen <zhanluxianshen@163.com>
### What problem does this PR solve?
Add test for document
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
### What problem does this PR solve?
Fix bugs in api.
Add simple examples for api.
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>