[Stupidu05]

• Adds an anonymized sample SQL dataset under data/sample/sample.sql containing 10 projects, 20 contracts spread across the 27-hour event window, links, and contributor handles (no avatars, locations, or personal profile fields).
• Adds hackproof seed (loads data/sample/sample.sql when the projects table is empty) and hackproof dump-sample (regenerates data/sample/sample.sql from a local database while stripping personal fields).
• Adds a one-shot seed service to docker-compose.yml before api starts.
• Documents the 5-command local dev workflow in docs/local-dev.md and adds unit tests in apps/api/tests/test_sample.py.

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Fixes #31
/claim #31

[vercel]

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