Publish curated GeoIntel source snapshot

CONTRIBUTING.md

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+# Contributing
+
+Keep GeoIntel changes reproducible, privacy-preserving and free from generated workspace state.
+
+- Branch from the protected default branch.
+- Use synthetic or explicitly redistributable imagery, coordinates and datasets in tests and documentation.
+- Do not commit `.codex-input` contents, SQLite/WAL/SHM files, archives, contact sheets, model outputs, private maps, credentials or local deployment data.
+- Document the origin, license and intended use of every external dataset, model and media asset.
+- Add tests for behavioural changes and run the documented backend, frontend, geospatial and managed validation gates.
+- Explain data-model, coordinate-system, model, privacy and deployment impact in the pull request.
+
+Report security issues according to `SECURITY.md`.