fix: correct pip install order so VLSearchImage is registered (fixes #234)

[octo-patch]

Fixes #234

Problem

The eval.sh script installs packages in the wrong order, causing VLSearchImage to be absent from TOOL_REGISTRY when agent_eval.py runs:

# OLD (broken) order
pip uninstall qwen-agent
pip install -e vl_search_r1/qwen-agent-o1_search --no-deps   # installs local fork with VLSearchImage
pip install "qwen-agent[code_interpreter]"                     # ← overwrites local fork with PyPI version!

Because pip install "qwen-agent[code_interpreter]" replaces the editable local install, VLSearchImage is no longer in TOOL_REGISTRY. When Qwen_agent is then instantiated with function_list=['web_search', 'VLSearchImage', 'visit', 'code_interpreter'], qwen-agent raises:

ValueError: Tool VLSearchImage is not registered.

Solution

Reverse the install order so the local fork (which adds VLSearchImage) is installed after the PyPI package has already pulled in all dependencies:

# NEW (correct) order
pip install "qwen-agent[code_interpreter]"                     # pulls in all deps first
pip install -e vl_search_r1/qwen-agent-o1_search --no-deps   # overrides with local fork; VLSearchImage stays registered

The pip uninstall qwen-agent step is also removed as it is unnecessary — pip install already replaces an existing installation.

Testing

Verified the eval.sh diff is minimal (3-line change) and that the install sequence now ends with the local fork active, ensuring VLSearchImage is in TOOL_REGISTRY when agent_eval.py initialises Qwen_agent.