fix(mail): resolve security draft CC before backend calls

[andreahlert]

Summary

When security_list is missing or blank, security reply drafts can lose their security CC. This change resolves the recipient in the shared mail-source contract before creating a draft, and applies the same rule to import, sync, invalidate, and CVE allocation.

The resolver uses the project list when configured. Otherwise, it warns and records cc_fallback, using security_inbox.foundation_security_address through project, organization, and framework precedence. If neither address is available, draft creation stops. Mailbox searches retain the existing <security-list> meaning.

OAuth and MCP draft recipes now reject missing or blank resolved CC values before invoking a backend. Documentation, the lifecycle spec, 13 configuration eval cases, and 11 recipe regression tests are included. Local agent artifacts are also excluded in .gitignore.

Type of change

• Skill change, with new eval fixtures
• Tool / bridge contract
• Documentation
• Python regression tests

Test plan

• prek run --all-files, including workspace lint, typing, tests, and documentation checks
• OAuth draft package: 92 tests passed, including 11 new recipe tests
• New security-CC eval step: 13/13 passed with Haiku
• New evals exercise missing/blank/template values, precedence, explicit null, deduplication, and stale fallback reset

A broader model-eval run during development returned 118/147 passing, with 29 failures outside the new CC step. Those failing cases had identical assembled prompts and fixtures on clean main; one failure was reproduced there, while other sampled failures varied between runs. This is not a claim that the complete model-eval suites are green. The final focused CC eval run passed all 13 cases.

RFC-AI-0004 compliance

• Vendor neutrality: the fallback comes from configuration, with ASF defaults supplied by its organization
• Write-access discipline: this changes draft creation only; existing human approval gates remain

Linked issues

Closes #181.

Notes for reviewers

An explicitly null or blank project-level foundation address disables that fallback rather than inheriting the organization value. This is a deliberate configuration choice for review, not a previously agreed requirement from the issue.

The shared resolver governs draft CC only; it does not redirect mailbox reads to a foundation inbox.

AI assistance disclosure

This change was developed with AI assistance from OpenAI Codex.