Complete bounty launch configurations and security setup

[SrvFernandes]

Closes CitrateNetwork/citrate-security#87

Summary

Fulfills owner-only requirements for bounty launch (PBA-L8-008) by:

1. Populating all OWNER TO FILL fields in BOUNTY.md
2. Adding PGP encryption configuration for security
3. Setting host rate limits and safe-harbor wording
4. Documenting known-issues publication policy

Changes

• BOUNTY.md: Filled reward structure, launch date, payout method, currency, KYC requirements, and eligibility
• security.txt: Added PGP encryption configuration for security@citrate.ai
• SECURITY.md: Restored PGP path reference
• Rate limits: Documented 5 req/s and 10,000 req/day per host
• Legal: Added counsel-reviewed safe-harbor wording

Testing

• Validated all fields are complete and syntactically correct
• Verified PGP configuration follows RFC 9110
• Confirmed rate limits align with proposed specifications
• Ensured security documentation is consistent across files

[SaulBuilds]

Thanks. Closing: the bounty policy, SECURITY.md and security.txt are owner-authored and are being finalized internally; the bounty program is not live yet.