Add LICENSE (Apache 2.0), CONTRIBUTING.md, SECURITY.md; move competition files

- LICENSE: Apache 2.0 with HAI-DEF Terms of Use notice for Gemma model
- CONTRIBUTING.md: setup guide, code style, areas for contribution
- SECURITY.md: responsible disclosure policy, patient data handling, LLM risks
- Moved download_data.txt, overview.txt, rules.txt to competition/ subfolder
- README.md: updated License section, added new files to Documentation Index

CONTRIBUTING.md

@@ -0,0 +1,82 @@
+# Contributing to CDS Agent
+
+Thank you for your interest in contributing to the Clinical Decision Support Agent!
+
+## Getting Started
+
+1. Fork the repository
+2. Clone your fork locally
+3. Follow the setup instructions in [README.md](README.md)
+4. Create a feature branch from `master`
+
+## Development Setup
+
+```bash
+# Backend
+cd src/backend
+python -m venv venv
+venv\Scripts\activate        # Windows
+pip install -r requirements.txt
+copy .env.template .env      # Add your Google AI Studio key
+
+# Frontend
+cd src/frontend
+npm install
+```
+
+## Running Tests
+
+```bash
+cd src/backend
+
+# RAG quality (no server needed)
+python test_rag_quality.py --rebuild --verbose
+
+# E2E pipeline (requires running backend on port 8002)
+python test_e2e.py
+
+# Clinical test suite
+python test_clinical_cases.py
+
+# External validation
+python -m validation.run_validation --medqa --max-cases 5
+```
+
+## How to Contribute
+
+### Reporting Issues
+
+- Use GitHub Issues for bug reports and feature requests
+- Include reproduction steps, expected behavior, and actual behavior
+- For clinical accuracy concerns, note the patient scenario and expected medical reasoning
+
+### Submitting Changes
+
+1. Create a branch: `git checkout -b feature/your-feature`
+2. Make changes with clear, focused commits
+3. Ensure existing tests still pass
+4. Submit a pull request with a description of what changed and why
+
+### Areas Where Contributions Are Welcome
+
+- **Clinical guidelines** — Adding new guidelines to `app/data/clinical_guidelines.json` (must cite authoritative sources: ACC/AHA, ADA, IDSA, etc.)
+- **Test cases** — Additional clinical scenarios in `test_clinical_cases.py`
+- **Validation harnesses** — Improving or adding dataset harnesses in `validation/`
+- **Frontend polish** — UI/UX improvements, accessibility, responsive design
+- **Documentation** — Corrections, clarifications, translations
+
+### Code Style
+
+- **Python:** Standard library conventions, type hints where practical, Pydantic models for data structures
+- **TypeScript/React:** Functional components, hooks, Tailwind CSS utility classes
+- **Commits:** Descriptive messages with a prefix (`feat:`, `fix:`, `docs:`, `test:`, `refactor:`)
+
+## Important Notes
+
+- **This is a medical AI project.** Changes to clinical reasoning, guidelines, or conflict detection require extra scrutiny. If you're not a domain expert, flag your PR for clinical review.
+- **No patient data.** Never commit real patient information. All test cases must be synthetic.
+- **API keys.** Never commit API keys or secrets. Use `.env` (gitignored).
+
+## License
+
+By contributing, you agree that your contributions will be licensed under the [Apache License 2.0](LICENSE).

LICENSE

@@ -0,0 +1,194 @@
+                                 Apache License
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+
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+
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+
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+   END OF TERMS AND CONDITIONS
+
+   Copyright 2025 bshepp
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
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+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+   ADDITIONAL NOTICE: This project uses the Gemma model, which is subject
+   to the Google HAI-DEF Terms of Use. See:
+   https://developers.google.com/health-ai-developer-foundations/terms

README.md

@@ -322,13 +322,17 @@ curl -X POST http://localhost:8000/api/cases/submit \
 | [docs/test_results.md](docs/test_results.md) | Detailed test results, RAG benchmarks, pipeline timing |
 | [DEVELOPMENT_LOG.md](DEVELOPMENT_LOG.md) | Chronological build history, problems solved, decisions made |
 | [docs/writeup_draft.md](docs/writeup_draft.md) | Project writeup / summary |
+| [CONTRIBUTING.md](CONTRIBUTING.md) | How to contribute to the project |
+| [SECURITY.md](SECURITY.md) | Security policy and responsible disclosure |
+| [TODO.md](TODO.md) | Next-session action items and project state |
 | [SUBMISSION_GUIDE.md](SUBMISSION_GUIDE.md) | Competition submission strategy |
-| [RULES_SUMMARY.md](RULES_SUMMARY.md) | Competition rules checklist |
 
 ---
 
 ## License
 
-Subject to [HAI-DEF Terms of Use](https://developers.google.com/health-ai-developer-foundations/terms) for model usage.
+Licensed under the [Apache License 2.0](LICENSE).
+
+This project uses the Gemma model, which is subject to the [HAI-DEF Terms of Use](https://developers.google.com/health-ai-developer-foundations/terms).
 
 > **Disclaimer:** This is a research / demonstration system. It is NOT a substitute for professional medical judgment. All clinical decisions must be made by qualified healthcare professionals.

SECURITY.md

@@ -0,0 +1,59 @@
+# Security Policy
+
+## Important Disclaimer
+
+**This is a research / demonstration system. It is NOT approved for clinical use and must NOT be used to make real medical decisions.** All clinical decisions must be made by qualified healthcare professionals.
+
+## Reporting a Vulnerability
+
+If you discover a security vulnerability in this project, please report it responsibly:
+
+1. **Do NOT open a public GitHub issue** for security vulnerabilities
+2. Email the maintainer directly (see GitHub profile for contact info)
+3. Include a description of the vulnerability, steps to reproduce, and potential impact
+
+We will acknowledge receipt within 48 hours and aim to provide a fix or mitigation within 7 days for critical issues.
+
+## Scope
+
+### In scope
+
+- Authentication/authorization bypasses (if auth is added in the future)
+- Injection vulnerabilities (prompt injection, SQL injection, command injection)
+- Sensitive data exposure (API keys, patient data leakage)
+- Dependency vulnerabilities in `requirements.txt` or `package.json`
+- CORS misconfigurations that could enable data exfiltration
+
+### Out of scope
+
+- Clinical accuracy of AI-generated recommendations (this is a known limitation, not a vulnerability)
+- Denial of service via expensive LLM calls (known limitation of the architecture)
+- Issues in third-party services (Google AI Studio, OpenFDA, RxNorm)
+
+## Security Considerations for This Project
+
+### Patient Data
+
+- This system processes clinical text that could contain protected health information (PHI)
+- **No real patient data should ever be used** with this demonstration system
+- In a production deployment, HIPAA compliance would require: encrypted storage, audit logging, access controls, and BAAs with all third-party services
+- The Gemma model can be self-hosted on-premises to avoid sending data to external APIs
+
+### API Keys
+
+- The Google AI Studio API key is stored in `.env` (gitignored)
+- Never commit `.env` or any file containing API keys
+- The `.env.template` file shows required variables without actual values
+
+### LLM-Specific Risks
+
+- **Prompt injection:** The system processes untrusted user input (patient text) that is sent to the LLM. Adversarial inputs could potentially manipulate LLM behavior.
+- **Hallucination:** The LLM may generate plausible but incorrect medical information. The conflict detection step and RAG grounding mitigate but do not eliminate this risk.
+- **Over-reliance:** The system is designed as decision *support*, not decision *making*. UI disclaimers and caveats are included to reinforce this.
+
+## Supported Versions
+
+| Version | Supported |
+|---------|-----------|
+| Current `master` branch | Yes |
+| Older commits | No |