SMT runner hardening checklist

[hyperpolymath]

Document and implement a checklist for SMT execution safety (timeouts, allow-list, cache, optional Rust runner) and user guidance.\n\nRefs: docs/wiki/Verification.md

[hyperpolymath]

✓ Completed in commit 3f14c53

Added comprehensive SMT runner security hardening section to docs/wiki/Verification.md:

Security Checklist:

1. ✓ Solver allow-list enforcement
2. ✓ Mandatory timeout configuration
3. ✓ Path validation
4. ✓ Result caching
5. 🔒 Optional Rust runner

Includes threat model, mitigations table, and production verification checklist.

See updated documentation for best practices and trade-offs.