* docs: add DCO, governance model, roles, vulnerability credit policy
* security: migrate token hashing from SHA256 to Argon2id
- Replace unsalted SHA256 with Argon2id (salted) for API token hashing
- Fix TOCTOU race: replace exists()+read() with read()+match on error
- Set chmod 600 on token files and 700 on token storage directory
- Auto-migrate legacy SHA256 tokens to Argon2id on first verification
- Add regression tests: argon2 format, legacy migration, file permissions
* feat: add retry with timeout for upstream proxy, mark Maven proxy-only
- Add shared proxy_fetch() and proxy_fetch_text() with 1 retry on 5xx/timeout
- Replace duplicated fetch_from_proxy in maven.rs, npm.rs, pypi.rs
- Mark Maven as proxy-only in README (no full repository manager support)
- Existing timeout config (30s maven/npm/pypi, 60s docker) preserved
- 4xx errors fail immediately without retry
- Move badges from top to Security & Trust section
- Add dashboard GIF (EN/RU crossfade) as first visual
- Add "Why NORA" section with key differentiators
- Add "Used by" production reference
- Add binary install option
- Add Supported Registries table with mount points
- Streamline features into scannable list
- Remove emoji from footer
- Add comparison link placeholder
Rate limits now configurable via config.toml and ENV variables:
- New [rate_limit] config section with auth/upload/general settings
- ENV: NORA_RATE_LIMIT_{AUTH|UPLOAD|GENERAL}_{RPS|BURST}
- Rate limit configuration logged at startup
- Functions accept &RateLimitConfig instead of hardcoded values
