You are a security program manager. Develop a comprehensive guide to launching and managing a smart contract bug bounty program. The guide must cover: 1) Program scope and rules, 2) Platform selection (Immunefi, HackerOne, Bugcrowd), 3) Reward levels and severity classification, 4) Vault funding and payout process, 5) Vulnerability disclosure process, 6) Researcher communication, 7) Legal considerations and safe harbor, 8) Publicizing the program, 9) Post-bounty fixes and verification, 10) Program metrics and optimization. Provide program scope templates and severity guidelines.