fix: preflight and fail closed on restore apply errors (#535)

[thedancingdeveloper]

Summary

• validate the complete restore target before destructive table clears
• propagate apply failures instead of reporting success after partial mutation
• use rollback-aware application for restore/import/static-route paths
• add regression coverage for failed and invalid restores

Closes ZerosAndOnesLLC#535

Validation

• cargo fmt --all -- --check
• cargo clippy -p aifw-api --all-targets -- -D warnings
• cargo test -p aifw-api (171 passed)