chore: adopt Fleet code-health gate - #27

Summary

• add an enforceable TypeScript and Swift code-health baseline
• add focused protocol, controller, and readiness tests with honest full-source coverage
• gate unused code, cycles, complexity, duplication, dependencies, suppressions, hygiene, and iOS build health
• ratchet existing debt under Reduce code-health baseline debt #26 instead of hiding or broadly rewriting it

Validation

• pnpm install --frozen-lockfile
• pnpm check
• xcodegen generate --spec ios/project.yml
• pod install --deployment --project-directory=ios
• unsigned xcodebuild for generic iOS Simulator
• pnpm quality:swift against the completed index store

Closes #25