### What problem does this PR solve?
The OpenAI-compatible chat endpoint
(`/chats_openai/<chat_id>/chat/completions`) was not returning accurate
token
usage in streaming responses. The token counts were either missing or
inaccurate because the underlying LLM API
responses weren't being properly parsed for usage data.
This PR adds proper token counting using tiktoken (cl100k_base encoding)
as a fallback when the LLM API doesn't provide usage data in streaming
chunks. This ensures clients always receive token usage information in
the
response, which is essential for billing and quota management.
**Changes:**
- Add tiktoken-based token counting for streaming responses in
OpenAI-compatible endpoint
- Ensure `usage` field is always populated in the final streaming chunk
- Add unit tests for token usage calculation
Fixes#7850
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
### What problem does this PR solve?
1) Create dataset using table parser for infinity
2) Answer questions in chat using SQL
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
This PR adds missing HTTP API test coverage for dataset
graph/GraphRAG/RAPTOR tasks, metadata summary, chat completions, agent
sessions/completions, and related questions. It also introduces minimal
HTTP test helpers to exercise these endpoints consistently with the
existing suite.
### Type of change
- [x] Other (please describe): Test coverage (HTTP API tests)
---------
Co-authored-by: Liu An <asiro@qq.com>
### What problem does this PR solve?
- Add new test suite for document app with
create/list/parse/upload/remove tests
- Update API URLs to use version variable from config in HTTP and web
API tests
### Type of change
- [x] Add test cases
### What problem does this PR solve?
- Move common constants (HOST_ADDRESS, INVALID_API_TOKEN, etc.) to
configs.py
- Update test imports to use centralized configs
- Clean up duplicate constant definitions across test files
This improves maintainability by centralizing configuration.
### Type of change
- [x] Refactoring test case
