Add automated tool review workflow

[valentin-vogel]

What changed

• adds a pull_request_target workflow for submitted-tool reviews
• extracts the proposed tool URL from the PR body, with a safe diff-text fallback
• uses the OpenAI Responses API with web search and structured JSON output
• reviews open-source status, GitHub source availability, no-code/low-code eligibility, legal/data-governance transparency, pricing, market fit, and overall "awesome" quality
• creates one persistent review comment and updates it on subsequent PR changes

Security

The privileged workflow always checks out the repository default branch and never checks out or executes contributor-controlled PR code. PR content and diffs are treated only as untrusted text input.

Configuration required

Add the repository Actions secret OPENAI_API_KEY before using the workflow.

The default model is gpt-5.4 and can be changed through OPENAI_MODEL in the workflow.

Validation

Compared the implementation branch against main: exactly three new files, no existing repository files modified.